Phytosynthesis of Nanoscale Materials

C H A P T E R

3 Phytosynthesis of Nanoscale Materials Mojtaba Salouti⁎, Fatemeh Khadivi Derakhshan† ⁎

Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran †Department of Microbiology, College of Science, Urmia Branch, Islamic Azad University, Urmia, Iran

O U T L I N E 1 Introduction 2 3

4

Advantages of Plant-Mediated Synthesis of Metal Nanoparticles

47

Green Synthesis of Metal Nanoparticles Using Plant Extracts 49 3.1 Method 49 Plant-Mediated Synthesis of Metal NPs 4.1 Leaf Extract and Fresh Leaf 4.2 Bark Extract and Stem Bark Extract 4.3 Stem Extract and Stem Latex 4.4 Rhizome Extract 4.5 Flower Extract 4.6 Fruit Extract 4.7 Peel Extract 4.8 Seed Extract 4.9 Root Extract 4.10 Latex and Latex Extract

Advances in Phytonanotechnology https://doi.org/10.1016/B978-0-12-815322-2.00003-1

4.11 Gum and Gum Extract 4.12 Plant Extract and Aqueous Extract 4.13 Other Tissues of Plants and Living Plant Systems

46

50 51 55 55 64 65 67 67 69 70 72

5 6 7

8

45

72 73 74

Biosynthesis of Bimetallic Nanoparticles

75

Biosynthesis of Metal Nanoparticles With Alga

75

Metal Nanoparticles Characterization 7.1 Qualitative Analysis 7.2 Quantitative Analysis

78 79 82

Various Factors Affecting the Morphology, Size, and Yield of Metal NPs 8.1 Plant Metabolites Affecting the Formation of Metal NPs

84 84

© 2019 Elsevier Inc. All rights reserved.

46

3.  Phytosynthesis of Nanoscale Materials

8.2 Culturing Factors Affecting the Formation of Metal Nanoparticles in Plants 9

Application of NPs Synthesized in Plants 9.1 Antibacterial Activity of Metal NPs 9.2 Antifungal Activity of Metal NPs 9.3 Larvicidal Activity of Metal Nanoparticles

90 94 95 96

9.4 Antiviral Effect of Metal Nanoparticles 9.5 Anticancer Effect of Metal Nanoparticles

97 98

10 Environmental Application of Metal Nanoparticles 99 11 Conclusion and Perspectives

100

References

101

97

1 INTRODUCTION Nanotechnology is a combination of principles involving biological, physical, and chemical techniques that create nanosized particles with specific functions. For this purpose, noble metal nanoparticles (NPs) like silver, gold, platinum, and palladium and nonmetallic, inorganic oxides like zinc oxide and titanium oxide have been widely exploited because of their unique electronic, mechanical, optical, chemical, and magnetic properties. NPs have unique properties, have large surface area to volume ratio, and are available in different sizes and shapes, such as spherical or rod. Therefore, they are used in various fields, such as diagnostic biological probes, optoelectronics, display instruments, catalysis, fabricating biological sensors, diagnosing or monitoring diseases like cancer cells, drug discovery, detecting environmental toxic metals or reagents, and in therapeutic applications (Menon et al., 2017; Khadivi Derakhshan et al., 2012; Karkaj et al., 2013; Salouti and Faghri Zonooz, 2017; Moghtader et al., 2014). Recently, different methods have been used to synthesize NPs such as physical (sonication, laser ablation, and radiation), chemical (condensation, sol-gel method, and reduction), and biological methods (Nadeem et al., 2017; Sheikhloo et al., 2011). The growth of metal NPs using physical or chemical methods is not healthy owing to the use of reducing agents, which are highly reactive or toxic in nature for human consumption or to the environment, and these are also quite expensive for upscale production (Makarov et  al., 2014; Mishra et al., 2015). Unfortunately, many of the nanoparticle synthesis or production methods involve the use of hazardous chemicals, low material conversions, high energy requirements, and difficult, wasteful purifications. The techniques using biosynthesis metal NPs, such as plant extracts and microorganisms (microalgae, macroalgae, yeast, fungus, actinomycete, bacteria, and viruses) as reductants and stabilizing agents could be considered alternatives for synthesis of inorganic NPs (Anbuvannan et al., 2015). Biological materials provide an environmentally friendly or greener chemical method to produce invaluable materials because the biomaterial-based routes eliminate the need to use harsh or toxic chemicals (Kharissova et al., 2013). These attractive properties make many biological entities efficient biological factories capable of significantly reducing environmental pollution



2  Advantages of Plant-Mediated Synthesis of Metal Nanoparticles

47

and ­reclaiming metals from ­industrial waste (Shah et  al., 2015). Biological synthesis can also provide an additional capping layer on synthesized NPs with the attachment of several biologically active groups, which can enhance the efficacy of biological NPs (Singh et al., 2016a). With the present state of nanotechnology, plants are better synthesizers as compared to the other biological methods due to the abundance of the availability of the plant resources when compared to other forms of biological resources (Prasad, 2014). Plant-based synthesis of NPs is in contrast faster, safer, and easier; it works at low temperatures, and requires only modest and environmentally safe components (Chung et al., 2016). It could be advantageous over microbial synthesis because there is easy culturing and maintenance of the cell (Prasad, 2014) and microbe-mediated synthesis is not very suitable for industrial feasibility because of the requirement for highly aseptic conditions and their maintenance (Roy and Das, 2015). Microorganisms can also be utilized to produce NPs but the rate of synthesis is slow and only a limited number of sizes and shapes are amenable compared to routes involving plant-based materials. Plants are able to reduce the metal ions faster than fungi or bacteria (Kharissova et al., 2013). According to the above, phytonanotechnology has advantages, including biocompatibility, scalability, and the medical applicability of synthesizing NPs using the universal solvent, water, as a reducing medium. Plant-derived NPs produced by readily available plant materials and the nontoxic nature of plants are suitable for fulfilling the high demand for NPs with applications in biomedical and environmental areas (Singh et  al., 2016a). The very first article on plant-mediated synthesis of silver nanoparticles (AgNPs) using alfalfa was reported in 2003 (Shankar et al., 2003b). Plant parts, such as roots, leaves, stems, seeds, rhizome, gum, flower, and fruits have also been utilized for NPs synthesis as their extract is rich in phytochemicals which act as both reducing and stabilization agents. The reduction and stabilization of metal ions by combination of biomolecules, such as proteins, amino acids, organic acid, vitamins, and secondary metabolites, such as flavonoids, alkaloids, polyphenols, terpenoids, heterocyclic compounds, and polysaccharides is already established in the plant extracts having medicinal values (Singh et al., 2016a; Akhtar and Swamy, 2015; Makarov et al., 2014; Noruzi, 2015). Control of the shape and size of metal NPs has been shown by either constraining their environmental growth (pH, temperature, incubation period, salt concentration, aeration, redox conditions, mixing ratio, and irradiation) or altering the functional molecules (Akhtar et al., 2013; Singh et al., 2016a; Wu et al., 2013). This chapter focuses on the role of plants as a biological system for the synthesis of metal NPs using plant extracts, factors responsible for reduction of metal nanoparticles, and medical applications of metal NPs in the worldwide research progressing in this field.

2  ADVANTAGES OF PLANT-MEDIATED SYNTHESIS OF METAL NANOPARTICLES It has long been known that plants are able to reduce metal ions both on their surface and in various organs and tissues remote from the ion penetration site (Makarov et  al., 2014). The biological synthesis of NPs is a cost-effective and ecofriendly method and is able to replace physical and chemical methods because the latter methods are toxic and costly.

48

3.  Phytosynthesis of Nanoscale Materials

The b ­ iological methods have shown to be better methods due to slower kinetics and they offer better manipulation on control over crystal growth and their stabilization. This has motivated an increase in research on the synthesis routes that allow better control of size and shape for a wide variety of nanotechnological applications (Prasad, 2014). The additional advantage of the biological synthesis of NPs is that it can reduce the number of required steps, including the attachment of some functional groups to the nanoparticle surface to make them biologically active, an additional step required in physiochemical synthesis (Singh et al., 2016a). The presence of biological components promotes an increase in the stability of the particles and may also facilitate, if necessary, the subsequent attachment of functional molecules, such as antibodies or DNA, to NPs. Consequently, nanomaterials have been synthesized using microorganisms and plant extracts. The use of plant extracts for synthesis of NPs is potentially advantageous over microorganisms due to the ease of scaling up the biohazards and elaborating the process of maintaining cell cultures. The use of environmentally benign materials, namely plant extracts, microorganisms, and enzymes for the synthesis of metal NPs offer plentiful benefits such as ecofriendliness, biocompatibility, nontoxicity, and cost effectiveness (Prasad, 2014). Microorganisms, such as bacteria, fungi, actinomycetes, yeasts, and viruses, are reported to have the innate potential to produce metal NPs either intra- or extracellularly and are considered as potential biofactories for nanoparticle synthesis. In the case of a microorganism, culturing methods are very important. Hence optimization of culturing parameters such as nutrients, light, medium pH, temperature, mixing speed, and buffer strength can significantly increase enzyme activity (Shah et al., 2015). Phytosynthesis, which utilizes parts of whole plants as biological factories to synthesize metallic NPs, is underexploited and could be an advantageous and profitable approach (Makarov et al., 2014). In recent years, the use of plant extracts has assumed great significance because plants are generally inexpensive, available, and nontoxic (Noruzi, 2015). With the present state of nanotechnology, plants are better synthesizers compared to the other biological methods due to the abundance of the availability of plant resources when compared to the other forms of biological resources (Prasad, 2014). In comparison to microorganisms, the phytosynthesis method is devoid of complex and multistep processes, such as microbial isolation, culturing, maintenance, etc., and is also very rapid and cost effective so that it can be easily scaled up for bulk production of NPs (Makarov et al., 2014). Use of plant extracts also reduces the cost of microorganism isolation and culture media enhancing the cost competitive feasibility over NPs synthesis by microorganisms (Prasad, 2014). In the synthesis methods based on plant extracts, the rate of reaction is relatively high, and the reaction takes several minutes to several hours to complete, depending on the plant type and the plant amount. But in microorganism-based methods, a long time (two or several days) is needed for microorganism cultures. This indicates that this method is a time-consuming approach (Noruzi, 2015). For instance, Ag and Au NPs have been synthesized using various plant extracts within 2 min (Okafor et al., 2013), 5 min (Bindhu et al., 2014; Franco-Romano et al., 2014; Saxena et al., 2012), 10 min (Arsiya et al., 2017; Ganesh Kumar et al., 2011; Masurkar et al., 2011; Singh et al., 2016b), 20 min (Karuppaiya et al., 2013), 30 min (Das et al., 2011; Guo et al., 2015; Krishnaraj et al., 2010), and 45 min (Singh et al., 2016c), highlighting the simple and fast synthesis of NPs using plant extracts (Makarov et al., 2014; Singh et al., 2016a). Furthermore, some microorganisms, such as Fuzarium spp, Pseudomonas spp, and Escherichia coli which are used to produce NPs, are extremely toxic and a threat to human



3 Green Synthesis of Metal Nanoparticles Using Plant Extracts

49

health, while most plants are safe and benign. Many plants, especially evergreen plants, are almost always available in nature. Plant extract-mediated synthesis of metallic NPs mainly occurs at room temperature, while in the synthesis of metallic NPs using microorganisms it is required to heat the reaction mixture or culture medium. For these reasons, plant extracts are more suitable for large-scale production than microorganisms (Noruzi, 2015). By using plant tissue culture techniques and optimizing the downstream processing, it is possible to synthesize metal NPs at industrial scale (Akhtar et  al., 2013). Moreover, agricultural crop wastes and food industry wastes are also excellent candidates for supplying sources of plantbased biochemicals with the potential to synthesize metallic NPs and similar products (Shah et al., 2015). In addition, the surfaces of biological NPs progressively and selectively adsorb biomolecules when they contact complex biological fluids, forming a corona that interacts with biological systems. These corona layers provide additional efficacy over bare biological NPs (Singh et  al., 2016a). Biological NPs synthesized by plants have been applied in many biomedical contexts, including anticancer and antimicrobial applications because of the higher efficacy of biological NPs compared with physiochemical NPs for biomedical applications. For instance, Mukherjee et al. showed the better efficacy of biological AgNPs and gold nanoparticles (AuNPs) biosynthesized from Olax scandens leaf in terms of anticancer activity, biocompatibility for drug delivery, and imaging facilitator activity compared with chemically synthesized silver and AuNPs. Furthermore, biological NPs showed high anticancer activity in the lung (A549), breast (MCF-7), and colon (COLO 205) cancer cell lines. These results showed significant inhibition of cancer cell proliferation and fluorescence imaging in A549 cancer cells (Mukherjee et al., 2013). Additionally, biological NPs are more biocompatible with the rat cardio myoblast normal cell line (H9C2), human umbilical vein endothelial cells (HUVEC), and Chinese hamster ovary cells (CHO), than chemically synthesized NPs, which further supports the future applications of biological NPs as drug delivery carriers (Makarov et al., 2014).

3  GREEN SYNTHESIS OF METAL NANOPARTICLES USING PLANT EXTRACTS In the biosynthesis of metallic NPs using plant extracts, three important parameters are metal salt, a reducing agent, and a stabilizing or capping agent for controlling the size of NPs and preventing their aggregation (Abou El-Nour et al., 2010). Plant extracts may act as both reducing agents and stabilizing agents in the synthesis of NPs. In producing NPs using a plant sample (such as leaf, stem, fruit, flower, root, peel, seed, and gum), the extract is simply mixed with a solution of the metal salt (such as AgNO3, HAuCl4, CuSO4, ZnNO3, PdCl2, TiO2, and PbSO4).

3.1 Method The first step is the preparation of the plant tissue extract. The collection of the plant part (root, fruit, leaf, bark, etc.) of interest from the available sites is done and then it is washed thoroughly, two or three times with tap water, to remove both epiphytes and necrotic plants, followed by washing with sterile distilled water to remove associated debris, if any is p ­ resent.

50

3.  Phytosynthesis of Nanoscale Materials

These clean and fresh sources are shade-dried for 10–15  days and then powdered using a domestic blender. For the plant broth preparation, around 10 g of the dried powder is boiled with 100 mL of deionized distilled water (hot percolation method). The resulting infusion is then filtered thoroughly until no insoluble material appears in the broth (Ahmed et al., 2016). Plant extract is added into the aqueous solution of metal ion at room temperature. The solution is shaken and boiled at a temperature range of 15°C–35°C from minutes to hours depending on the plant extract. The extract is cooled to room temperature and filtered using filter paper. The second step is the synthesis of metal NPs by plant tissue extract. For this purpose, an aqueous solution of metal salt (such as AgNO3, HAuCl4, or CuSO4) is prepared in Erlenmeyer flasks and plant tissue extract is added to a metal salt aqueous solution in an Erlenmeyer flask and is heated in a water bath or incubator. Of course, a stoichiometric amount of metal salt is added to plant tissue extract and then is mixed thoroughly by a magnetic stirrer. This reaction mixture is incubated further to reduce the metal salt and considered for any change in color. This is the first qualitative indication that NPs are being formed. For example, the appearance of brownish red color and faint yellow color in the reaction solutions indicate the formation of gold and AgNPs, respectively (Kasthuri et al., 2009b; Krishnaraj et al., 2010). The change of deep blue color of the copper salt solution to green, due to the formation of copper NPs, is another example (Hariprasad et al., 2016). Addition of plant extract into the palladium ion solution exhibits the gradual change in color from transparent orange to dark brown (Kalaiselvi et al., 2015) and color change from half white to pale yellow represents the synthesis of ZnO NPs (Santhoshkumar et al., 2017). In the third step, the fully reduced solution is centrifuged. The supernatant liquid is discarded and the pellet obtained is redispersed in deionized water. The centrifugation process is repeated two to three times to wash off any absorbed substances on the surface of the metal NPs. The pale precipitate is then taken out and washed repeatedly with distilled water followed by ethanol to remove the impurities. Then a pale powder of metal NPs is obtained after drying at 60°C in an oven overnight. In the fourth step, metal NPs are generally characterized by their size, shape, surface area, and dispersity by various quantitative and qualitative techniques. The nature of plant extract, its concentration, the concentration of the metal salt, the pH value, temperature, and contact time are known to affect the rate of production of NPs, their quantity, and other characteristics (Hariprasad et al., 2016). Plant extracts have the potential to produce NPs with a specific size, shape, and composition (Shah et al., 2015).

4  PLANT-MEDIATED SYNTHESIS OF METAL NPS Plants are the most preferred source of NPs synthesis because they lead to large-scale production and production of stable NPs, varied in shape and size. Plant parts, such as leaf, stem, root, fruit, and seed have been used for metal NPs synthesis because of the exclusive phytochemicals that they produce. Using natural extracts of plant parts is a very ecofriendly, cheap process and it does not involve usage of any intermediate base groups. These natural plant extracts secrete some phytochemicals that act as both reducing agents and capping or stabilization agents (Agarwal et al., 2017). A number of plants are currently being investigated for their role in the synthesis of NPs.



4  Plant-Mediated Synthesis of Metal NPs

51

4.1  Leaf Extract and Fresh Leaf Plant leaf extract has been used for synthesis of silver, gold, zinc oxide, copper, palladium, platinum, and titanium oxide NPs, which leads to formation of pure metallic NPs of Ag, Au, ZnO, CuO, Pd, Pt, and TiO2. Leaf extracts can be used as reducing agents, capping agents, or both in green synthesis of metal NPs using plants (Amin et al., 2012). 4.1.1  Silver Nanoparticles Shankar et al. (2003b) reported the synthesis of AgNPs using leaf extract of Pelargonium graveolens ranged in size from 16 to 40 nm. Bioactive silver nanoparticle synthesis was investigated by Dubey et al. (2009) using the methanolic biomass of Eucalyptus hybrida leaf at ambient temperature. The flavanoid and terpenoid constituents that are present in Eucalyptus hybrida leaf extract were found in the surface active molecules stabilizing the NPs (Dubey et al., 2009). The antimicrobial activity of Solanum torvum leaf extract mediated AgNPs (an average size of 14 nm) within 60 min was performed against pathogenic bacteria and fungi of silkworm Bombyx mori (Govindaraju et al., 2010). The leaf extract of Argimone mexicana was used by Singh et al. (2010a,b) for synthesis of AgNPs (within 4 h) with particle size in the range of 10–50 nm. They reported the antibacterial effects of AgNPs obey a dual action mechanism (investigated against Escherichia coli, Pseudomonas aeruginosa, and Aspergillus flavus): the bactericidal effect of Ag+ and membrane-disrupting effect of the polymer subunits (Singh et al., 2010a). Recently synthesized natural products for vector control have been found to be a priority to produce insecticides. Rajakumar and Abdul Rahuman (2011) investigated the larvicidal activity of synthesized AgNPs produced by aqueous extract of Eclipta prostrata, a member of the Asteraceae. The effect of AgNPs was studied against fourth instar larvae of filariasis vector, Culex quinquefasciatus and malaria vector Anopheles subpictus Grass (Rajakumar and Abdul Rahuman, 2011). Rapid biosynthesis of AgNO3 with the size range of 3–20 nm within 8 min using leaf broth of Ocimum sanctum as reductant and stabilizer was reported by Singhal et al. (2011). The produced AgNPs were surrounded by a faint thin layer of proteins and metabolites, such as terpenoids having functional groups of amines, alcohols, ketones, aldehydes, and carboxylic acids (Singhal et al., 2011). Masurkar et  al. (2011) reported the formation of AgNPs within 8–10 minutes by microwave irradiation to aqueous solution of AgNO3 (1 mM, pH 8) mixed with fresh leaf extract of Cymbopogan citratus. TEM analysis revealed that the AgNPs are prominently spherical with average size of 32 nm (Masurkar et al., 2011). Kaviya and Viswanathan (2011) reported that when the Polyalthia longifolia leaf extract was mixed in the aqueous solution of the silver ion complex and D-sorbitol, the change in color of the solution to yellowish brown due to the reduction of silver ions. In the concentration of 10−3 M, the size of synthesized nanoparticles was 50 and 35 nm at 25°C and 60°C, respectively. Similarly, in the case of 10−4 M concentration, the size of synthesized nanoparticles was reported as 20 and 15 nm at 25°C and 60°C, respectively (Kaviya and Viswanathan, 2011). Svensonia hyderabadensis leaf extract was used to synthesize spherical shape of AgNPs with the size around 45 nm (at room temperature after 48 h). They showed antifungal activity of produced silver nanoparticles against Aspergillus niger, Fusarium oxysporum, Curvularia lunata, and Rhizopus arrhizus (Linga Rao and Savithramma, 2012). Five plant leaf extracts

52

3.  Phytosynthesis of Nanoscale Materials

(Malva parviflora, Beta vulgaris subsp. Vulgaris, Anethum graveolens, Allium kurrat, and Capsicum frutescens) were screened for their bioreduction behavior for synthesis of AgNPs by Zayed et al. (2012) M. parviflora (Malvaceae) was found to exhibit the best reducing and protecting action in terms of synthesis rate and monodispersity of the prepared AgNPs (19–25 nm). FTIR analysis proved that particles were reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass (Zayed et al., 2012). Justin et al. (2012) described an ecofriendly technique for green synthesis of spherical AgNPs with 18–41 nm in size using the extract of Piper longum leaf as a reducing and capping agent. They reported the excellent cytotoxic effect of AgNPs on HEp-2 cell line too (Justin et al., 2012). Synthesis of AgNPs using a leaf extract of Ficus benghalensis was reported by Saxena et al. (2012). They found a fast and convenient method for the synthesis of AgNPs within 5 min without using any harsh conditions and NPs had an average size of 16 nm (Saxena et al., 2012). Biosynthesis of stable AgNPs using Melia azedarach was explained by Sukirtha et al. (2012). They showed the cytotoxicity of AgNPs against HeLa cells in vitro and against Dalton’s ascites lymphoma in a mouse model (Sukirtha et al., 2012). The activity of AgNPs produced by Murraya koenigii plant leaf extract was studied against first to fourth instar larvae and pupae of Anopheles stephensi and Aedes aegypti. The synthesized AgNPs from M. koenigii leaf were found to be more toxic than crude leaf ethanol extract in both mosquito species (Suganya et al., 2013a). Ramteke et al. (2013) reported that the AgNPs were stabilized by eugenols, terpenes, and other aromatic compounds present in the leaf extract of Ocimum sanctum (Tulsi), investigated by FTIR analysis. Such AgNPs stabilized by Tulsi leaf extract were found to have enhanced antimicrobial activity against well-known pathogenic strains, namely Staphylococcus aureus and E. coli (Mallikarjun et al., 2011; Ramteke et al., 2013). Biosynthesis of AgNPs was demonstrated by Carrillo-López using extract of Chenopodium ambrosioides at room temperature (25°C). Two molar solutions of AgNO3 (1 and 10 mM) and five extract volumes (0.5, 1, 2, 3, and 5 mL) were used to assess the different quantities, shapes, and size of the particles. The smallest particle sizes (4.9 and 5.1 nm) were obtained using 1 mL of leaf extract with 10 and 1 mM AgNO3. Using 3 and 5 mL of bioreducing, the average particle sizes were 7 and 8.5 nm (Carrillo-López et al., 2014). Kathiravan et al. (2014) described synthesis of AgNPs (diameter 7.3 nm) using leaf extract of Melia dubia. AgNPs showed remarkable cytotoxicity activity against KB cell line with evidence of high therapeutic index value. 4.1.2  Gold Nanoparticles Shankar et  al. (2003a,b) reported the use of Geranium leaves (Pelargonium graveolens) in the extra-cellular synthesis of decahedral, icosahedral, triangular, and rod-shaped AuNPs. Sterilized Geranium leaves were exposed to aqueous Au ions. Rapid synthesis of the stable AuNPs was observed after 48 h with different sizes (16–40 nm) (Shankar et  al., 2003a). Khaleel Basha et al. (2010) demonstrated the rapid formation of AuNPs by guavanoic acid, a phytochemical of Psidium guajava leaf extract. The produced AuNPs showed antidiabetic activity by Protein Tyrosine Phosphatase 1B inhibition representing a significant advance in nanomaterial with realistic implications (Khaleel Basha et al., 2010). Synthesis of stable and spherical AuNPs with well-defined dimensions of average size of 15–25 nm using Cassia auriculata aqueous leaf extract was reported by Kumar et al. (2011). The reduction of auric chloride led to the formation of AuNPs within 10 min at 28°C at a wide range of pH [3.4–10.2]



4  Plant-Mediated Synthesis of Metal NPs

53

(Ganesh Kumar et al., 2011). Biosynthesis of anisotropic AuNPs using aqueous leaf extract of Madhuca longifolia was demonstrated by Mohammed Fayaz et al. (2011). The hydroxyl group in tyrosine residue was found to be responsible for reduction of noble metal ions (Mohammed Fayaz et al., 2011). Synthesis of cationic AuNPs using Peunut leave extract for biological applications was reported by Raju et al. (2014). AuNPs were of different shapes, bigger in size (110–130 nm), and well separated. The formed cationic AuNPs uphold the applications in gene delivery, where DNA is loaded onto the particles and is carried into the cells. This biomaterial can be used for efficient gene delivery (Raju et al., 2014). The biosynthesis of AuNPs took only 3.5 min using Pelargonium zonale leaf extract under ambient conditions reported by Franco-Romano et al. (2014). P. zonale leaf extract was used as a stabilizing agent in a sonocatalysis process based on high-power ultrasound. A total of 80% of the AuNPs obtained in this way have a diameter in the range 8–20 nm, with an average size of 12 ± 3 nm (Franco-Romano et al., 2014). Two medicinally important plants—Cucurbita pepo and Malva crispa leaf extracts—were also reported by Chandran et  al. (2014) for synthesis of AuNPs with potent antibacterial activity against food spoilage pathogens. Respectively, the phenolic and polyphenol substances present in the plant leaf extracts of C. pepo and M. crispa was found to play a major role in the AuNPs synthesis (Chandran et  al., 2014). The Ag and Au NPs synthesized using Butea monosperma leaf extract were reported by Patra et  al. (2015). Both AuNP and AgNP were stable in biological buffers and the TEM image of AuNPs indicated the NPs were highly monodispersed and consist of mainly hexagonal AuNPs (15–35 nm), triangular (30–100 nm), few rods (50–75 nm), and spherical shaped (10–30 nm). The prepared AgNPs clearly were large with spherical shape (20–80 nm) along with a few triangular. The role of –OH groups as a reducing agent for the formation of NPs was demonstrated by FTIR (Patra et al., 2015). Mata et al. (2016) described the green synthesis of AuNPs using Abutilon indicum leaf extract and their cytotoxic mechanism against colon cancer cells and good antioxidant activity (Mata et al., 2016). AuNPs (11 and 14 nm) were successfully prepared via facile biosynthesis of Chenopodium murale leaf extract. γ-Irradiation-induced strategy also offered AuNPs with distribution of narrower size. The –COOH groups of phenolics and flavonoids in the leaf extract were found to be the main reason for the reduction of gold ions while, CO groups and CN groups contributed in the stabilization of NPs (Abdelghany et al., 2017). 4.1.3  Zinc Oxide Nanoparticles Elumalai and Velmurugan (2015) described the synthesis of ZnO NPs using fresh leaf aqueous extract of Azadirachta indica. XRD study reveals that the biosynthesized ZnO NPs exhibits a spherical shape structure with an average size of 18 nm (9.6–25.5 nm confirmed by TEM). Phenolic acid and flavonoid compounds were found to play a major role in bioreduction reaction confirmed by FT-IR. Antimicrobial activities of green synthesized ZnO NPs were more potent than Bare ZnO and leaf extract of A. indica (Elumalai and Velmurugan, 2015). ZnO NPs were synthesized using leaf extract of Anisochilus carnosus reported by Anbuvannan et al. (2015). The structural analysis demonstrated that the prepared ZnO NPs were crystalline and exhibited hexagonal wurtzite, quasi-spherical structure with different sizes (Anbuvannan et al., 2015). Ochieng et al. (2015) successfully described ZnO NPs biosynthesis using Spathodea campanulata as the reducing and stabilizing agent. TEM analysis ­demonstrated that the ZnO

54

3.  Phytosynthesis of Nanoscale Materials

NPs had nearly spherical shapes and had size range of 20–50 nm. The phytochemicals involved in the synthesis and stabilization of the ZnO NPs can be presumed to be polyphenols and proteins (Ochieng et  al., 2015). Madan et  al. (2016) demonstrated the biosynthesis of ZnO NPs using fresh leaf extract of Azadirachta indica. XRD and TEM studies revealed that the ZnO NPs exhibited a hexagonal disk and nanobuds with an average size of 9–40 nm and 10–30 nm, respectively. The NPs indicated superior photocatalytic activity for the decolorization of Methylene blue under Sunlight and UV light (Madan et al., 2016). ZnO NPs were biosynthesized using terpenoid (TAP) fractions isolated from Andrographis paniculata leaves reported by Kavitha et al. (2017). Subsequently, the ZnNO3 (0.1 N) was treated with the isolated TAP fractions to biosynthesize Zinc oxide NPs (Zn-TAP NPs). From SEM and XRD analyses, it was found that the hexagonal nanorod particle was 20.23 nm in size and +17.6 mV of zeta potential. It was proposed that it can be easily absorbed by negatively charged cellular membrane and then contributes to efficient intracellular distribution of drugs (Kavitha et al., 2017). Biosynthesis of ZnO NPs using Calotropis procera leaves for the photodegradation of methyl orange demonstrated by Gawade et al. (2017). The XRD pattern approved that ZnO NPs associated to hexagonal wurtzite structure. TEM images showed that the particles of ZnO have spherical shape with size ranging from 15 to 25 nm (Gawade et al., 2017). 4.1.4  Other Metal Nanoparticles Song et al. (2009a,b) reported ecofriendly extracellular synthesis of platinum NPs (2–12 nm) from an aqueous H2PtCl6·6H2O solution using the leaf extract of Diopyros kaki as a reducing agent. A greater than 90% conversion of platinum ions to NPs was achieved with a reaction temperature of 95°C and a leaf broth concentration of >10% (Song et al., 2009b). Soundarrajan et al. (2012) used leaf extract of Ocimum sanctum for the synthesis of platinum NPs from an aqueous chloroplatinic acid. A greater conversion of platinum ions to NPs was achieved by employing a tulsi leaf broth with a reaction temperature of 100°C. The reduced platinum showed similar hydrogen evolution potential and catalytic activity to pure platinum using linear scan voltammetry. FTIR revealed that compounds such as ascorbic acid, gallic acid, terpenoids, certain proteins, and amino acids act as reducing agents for platinum ions reduction (Soundarrajan et al., 2012). Palladium NPs (PdNPs) synthesizing using protein rich soybean leaf extract was reported by Kumar et al. (2012a,b). The proteins and some of the amino acids that exist in soybean leaf extracts were actively involved in the reduction of palladium ions. The average size of Pd NPs was around 15 nm (Kumar et al., 2012a). Synthesis of Titanium dioxide NPs (TiO2 NPs) utilizing leaf aqueous extract of Catharanthus roseus was described by Velayutham et al. (2012). Synthesized TiO2 NPs were clustered and irregular shapes, mostly aggregated and having the size of 25–110 nm, and showed antiparasitic activities (Velayutham et  al., 2012). Zahir and Indira (2015) reported the synthesis of spherical TiO2 NPs (81.7–84.7 nm) using aqueous leaf extract of Euphorbia prostrata at 40°C, pH 8.0 within 10 h (Zahir and Indira, 2015). Naseem and Farrukh (2015) described synthesis of Hexagonal Iron NPs using the leaf ­extract of Lawsonia inermis and Gardenia jasminoides plants. TEM and SEM images of synthesized FeNPs using L. inermis and G. jasminoides showed the production of NPs with the average size of 21 and 32 nm, respectively. The produced iron NPs showed good antibacterial activity against human pathogens (Naseem and Farrukh, 2015).



4  Plant-Mediated Synthesis of Metal NPs

55

The Camellia Sinensis leaf extract was employed for the synthesis of nickel NPs (NiNPs) by Bibi et al. (2017a,b). The NPs were characterized by SEM, EDX, XRD, and VSM techniques. The photocatalytic activity (PCA) of NiNPs was evaluated by degrading crystal violet (CV) dye. The NiNPs size was in the range of 43.87–48.76 nm, spherical in shape and uniformly distributed with magnetization saturation of 0.073 emu/g. NiNPs showed promising photocatalytic activity (Bibi et al., 2017a). Chung et al. (2017) reported the synthesis of Copper NPs by mixing copper acetate solution with leaf extract of Eclipta prostrata without using any surfactant or external energy. E. prostrata leaf extract functioned as an excellent reducing agent for copper ions, and formation of CuNPs with an average size of 31 ± 1.2 nm (Chung et al., 2017). Table 1 summarizes some of the reports pertaining to nanoparticle synthesis mediated by the leaf extracts of various plants.

4.2  Bark Extract and Stem Bark Extract Sathishkumar et al. (2009a,b) and Munnaluri et al. (2015) reported the synthesis of quasispherical and small, rod-shaped AgNPs from silver precursor using the bark extract and powder of Cinnamon zeylanicum. They reported that the bark extract produced more Ag NPs than the powder did, which was attributed to the large availability of the reducing agents in the bark extract. Size distribution of produced AgNPs was in the range of 30 to 150 nm. The NPs was found to have antibacterial activity against Escherichia coli BL-21 strain (Sathishkumar et al., 2009b; Munnaluri et al., 2015). Ankanna et al. (2010) reported the synthesis of highly dispersed AgNPs in the range size of 30–40 nm using a dried stem bark of Boswellia ovalifoliolata extract as the reducing agent (Ankanna et al., 2010). Daisy and Saipriya (2012) described reduction of gold ions by Cassia fistula stem bark in the form of stable AuNPs with different morphologies. The produced AuNPs showed promising antidiabetic properties (Daisy and Saipriya, 2012). Biosynthesis of spherical AuNPs using bark water extract of Eucommia ulmoides was reported by Guo et al. (2015) at optimum temperature of 50ºC and pH 9 within 30 min. The average size of AuNPs measured by DLS was determined 18.2 nm (Guo et al., 2015). Various plants have been used for the synthesis of metals nanoparticles by bark extract as shown in Table 2, as reported in the literature.

4.3  Stem Extract and Stem Latex Valodkar et al. (2011) demonstrated the synthesis of Ag and Cu NPs (5–10 nm) even at high concentrations using the stem latex of Euphorbia nivulia. The major component of the latex, Euphol, is assumed to be the reducing moiety, while stabilization is assisted by certain peptides and terpenoids present within the latex as supported by the FT-IR analysis (Valodkar et al., 2011). The stem extract of Calotropis procera was used by Gondwal and Pant (2013) for synthesis of spherical Ag NPs with particle size in the range of 26–38 nm (Gondwal and Pant, 2013). Phytosynthesis of AgNPs using Cissus quadrangularis extract was reported by Vanaja et al. (2013) at room temperature. The stem part of plant extract showed many different functional groups, particularly carboxyl, amine, and phenolic compounds involved in the reduction of silver ions (Vanaja et al., 2013). Production of spherical AgNPs with size ranging from 3 to 31 nm and spherical AuNPs with the size ranging from 5 to 20 nm using Hibiscus cannabinus stem extract for 5 min at room temperature was reported by Bindhu et al. (2014). Table 3 shows metal nanoparticles synthesized by stem extract and stem latex of different plants.

56

3.  Phytosynthesis of Nanoscale Materials

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts Plant

Metal

Size (nm)

Shape

Reference

Pelargonium graveolens

Ag

16–40

Crystalline

Shankar et al. (2003b)

Decahedral, icosahedral, rod, triangular

Shankar et al. (2003a)

Triangular, spherical, hexagonal, cubic

Sangaru et al. (2004)

Spherical

Shankar et al. (2004)

Au Cymbopogon flexuosus (Lemongrass)

Au

Azadirachta indica

Ag

41–60

Au-core

10–35

Ag

15–70

Spherical

ZnO

9.6–25.5

Spherical

ZnO

10–15

MgO

43 (PSA)

Hexagonal, cubic

Moorthy et al. (2015)

CeO2

231(FESEM)

Uniform

Sharma et al. (2017)

Terminalia catappa

Au

10–35

Spherical

Ankamwar et al. (2005a)

Aloe vera

Au

50–235

Triangular

Chandran et al. (2006)

Ag

15.2 ± 4.2

Spherical

Laokula et al. (2008)

In2O3

5–50

Spherical

Qian et al. (2015)

ZnO

25–65

Spherical, hexagonal

Se Ag

–

–

Shikuo et al. (2007) Li et al. (2007)

55–80 3.2– 6.0

Triangular, spherical Spherical

Jiale et al. (2007) Yang et al. (2010)

Capsicum annuum

200–500

Ag

Cinnamomum camphora Ag and Au Pd

Rai et al. (2007)

Poopathi et al. (2015) and Prathna et al. (2011) Elumalai and Velmurugan (2015)

Coriandrum sativum

Au

6.75–57.9

Spherical

Narayanan and Sakthivel (2008)

Camelia sinensis (green tea)

Ag and Au Ni ZnO

30–40 44–49 8 ±.5

Spherical, triangular, irregular Spherical, uniform Spherical, hexagonal

Vilchis-Nestor et al. (2008) Moulton et al. (2010) Bibi et al. (2017a) Nava et al. (2017)

Eucalyptus hybrida

Ag

50–150

uniform

Dubey et al. (2009)

Datura metel

Ag

16–40

Spherical

Kesharwani et al. (2009)

Diopyros kaki

Au Pt

5–300 15–19

Triangles, pentagons, hexagons Crystalline

Song et al. (2009a) Song et al. (2009b)

Magnolia kubos

Ag Au Cuo

15–500 5–300 37–110

Spherical. Spherical, triangles, pentagons, hexagons. Spherical

Song and Kim (2009) Song et al. (2009a) Lee et al. (2013)



57

4  Plant-Mediated Synthesis of Metal NPs

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Pelargonium graveolens

Ag

1–10

Uniform

Safaepour et al. (2009)

Phyllanthin amarus

Au and Ag

10–110

Anisotropic, spherical

Kasthuri et al. (2009a)

Platanus orientalis

Ag

15–500

Cubic

Song and Kim (2009)

Zingiber officinale

Au and Ag

10 and 30.31

Spherical

Singh et al. (2002)

Solanum torvum

Ag

~14

Spherical

Govindaraju et al. (2010)

Cassia fistula

Ag

50–60

Nanowire

Lin et al. (2010)

Lippia citriodora

Ag

15–30

Spherical

Cruz et al. (2010)

Argimone mexicana

Ag

10–50

Cubic, hexagonal

Singh et al. (2010a)

Sesuvium portulacastrum

Ag

5–20

Spherical

Nabikhan et al. (2010)

Hibiscus rosasinensis

Ag and Au

~14

Triangular, hexagonal, dodecahedral, spherical

Philip (2010)

Rosa rugosa

Ag and Au

12 and 11

Spherical—triangular, hexagonal

Dubey et al. (2010)

Coleus amboinicus

Au

4–55

Spherical, triangle, hexagonal, decahedral

Narayanan and Sakthivel (2010)

Psidium guajava

Au SnO2

4–24 8–10

Spherical –

Khaleel Basha et al. (2010) Kumar et al. (2018)

Mangifera indica

Au Ag

17–20 20

Spherical, triangular Spherical, triangular, hexagonal

Philip (2010)

Acalypha indica

Ag Au

20–30 <30

Spherical Spherical

Krishnaraj et al. (2010) Krishnaraj et al. (2014)

Euphorbia hirta

Ag

40–50

Spherical

Elumalai et al. (2010)

Stevia rebaudiana

Ag Au

2–50 17

Spherical Spherical, uniform

Sadeghi et al. (2015a) and Yilmaz et al. (2011)

Mentha piperita

Au Ag

150 90

Spherical Spherical

Mubarak Ali et al. (2011)

Garcinia mangostana

Ag

5–60

Spherical

Veerasamy et al. (2011)

Vitex negundo

Ag

18.2 ± 8.9

Spherical

Zargar et al. (2011)

Cymbopogan Citratus

Ag

~32

Spherical

Santhoshkumar et al. (2011)

Nelumbo nucifera

Ag

25–80

Spherical, triangle, decahedral

Santhoshkumar et al. (2011)

Polyalthia longifolia

Ag

15–50

Spherical

Kaviya and Viswanathan (2011)

Rosa indica

Au

23.5–60.8

Spherical

Udayasoorian et al. (2011)

Continued

58

3.  Phytosynthesis of Nanoscale Materials

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Nicotiana tobaccum

Ag

8

Crystalline

Suranjit Prasad Darshit Pathak et al. (2011)

Memecylon edule

Au

SEM:20–50 TEM:10–45

Triangular, circular, hexagonal

Elavazhagan and Arunachalam (2011)

Arachis hypogaea

CuO

–

–

Ramesh et al. (2011)

Cassia auriculata

Ag Au CuO

20–40 15–25 23

Spherical Spherical Spherical

Udayasoorian et al. (2011) Ganesh Kumar et al. (2011) Shi et al. (2017)

Madhuca longifolia

Au

7 nm–3 μm

Triangular

Mohammed Fayaz et al. (2011)

Eclipta prostrata

Ag Pd CuO

35–60 63 ± 1.4 31±1.2

– Uniform Spherical, hexagonal, cubical

Rajakumar and Abdul Rahuman (2011) Rajakumar et al. (2015) Chung et al. (2017)

Ocimum sanctum

Ag Au and Ag Pt Cu ZnO

3–20, 18 30, 10–20 23 77 50

Spherical Hexagonal Irregular – Hexagonal (wurtzite)

Mallikarjun et al. (2011), Ramteke et al. (2013), Philip and Unni (2011), and Soundarrajan et al. (2012) Kulkarni and Kulkarni (2013) Abdul Salam et al. (2014)

Moringa oleifera

Ag ZnO

57 12–30.5

Spherical Spherical, nanorod

Prasad and Elumalai (2011) Matinise et al. (2017)

Arbutus unedo

Ag

3–20

Spherical

Kouvaris et al. (2012)

Malva parviflora

Ag

19–25

Spherical

Zayed et al. (2012)

Ficus benghalensis

Ag

~16

Spherical

Saxena et al. (2012)

Ocimum tenuiflorum

Ag

25–40

Spherical

Patil et al. (2012)

Tridax procumbens

Ag

55

–

Dhanalakshmi and Rajendran (2012)

Svensonia hyderabadensis

Ag

45

Spherical

Linga Rao and Savithramma (2012)

Piper longum

Ag

18–41

Spherical

Justin et al. (2012)

Crossandra infundibuliformis

Ag

~38

Flake-like

Kaviya et al. (2012)

Melia azedarach

Ag

78

Cubical, spherical

Sukirtha et al. (2012)

Glycine max

Pd

15

Uniformly

Petla et al. (2012)

Piper betle

Ag Pd

3–37 4

Spherical Uniformly

Koduru et al. (2012) Koduru et al. (2013)

Annona squamosal

Ag

20–100

Spherical

Vivek et al. (2012)

Anacardium occidentale

Pd Pt

2.5–4.5 –

Spherical Irregular rod

Sheny et al. (2012) Sheny et al. (2013)



59

4  Plant-Mediated Synthesis of Metal NPs

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Calotropis gigantean

Ag ZnO CuO

18–41 30–35 20

Spherical Spherical Spherical

Baskaralingam et al. (2012) Vidya et al. (2013) Sharma et al. (2015)

Catharanthus roseus

TiO2 Pd

25–110 38

Clustered, irregular Spherical

Velayutham et al. (2012) and Kalaiselvi et al. (2015)

Tithonia diversifolia

Ag

~25

Roughly circular

Tran et al. (2013)

Thuja occidentalis

Ag

7–14

–

Barua et al. (2013)

Premna herbacea

Ag

10–30

Spherical

Kumar et al. (2013)

Centella asiatica

Ag

30–50

Spherical

Rout et al. (2013)

Calotropis procera

Ag ZnO

19–45 15–25

Spherical Spherical

Gondwal and Pant (2013) Gawade et al. (2017)

Capparis spinose

Ag

>80

Spherical

Gogoi (2013)

Prosopis chilensis

Ag

11.3 ± 2.1

Spherical

Kandasamy et al. (2013)

Eucalyptus angophoroides Ansevieria trifasciata Impatiens scapiflora

Ag

3–9

Spherical

Okafor et al. (2013)

Citrullus colocynthis

Ag

44

Spherical

Vanaja and Annadurai (2013)

Eucalyptus macrocarpa

Au Ag

20–100 10–100 10–50 38 (XRD)

Spherical, triangular, hexagonal Spherical Cubic Crystallite

Poinern et al. (2013a) Poinern et al. (2013b)

Albizia adianthifolia

Ag

4–35

Spherical

Gengan et al. (2013)

Cacumen platycladi

Au

–

Variable

Wu et al. (2013)

Podophyllum hexandrum

Ag

14

Spherical

Jeyaraj et al. (2013)

Olax scandens

Au

5–15

Spherical

Mukherjee et al. (2013)

18–55

Rod shape

30–55

Dumbbell shape

30–100

Triangular

15–35

Hexagonal

Ag

20–60–90

Spherical

Mukherjee et al. (2014)

Ag CuO Au

48–67 – 10

Cubic, uniform – Spherical

Roni et al. (2013) Gopinath et al. (2014) Tahir et al. (2015)

Nerium oleander

Continued

60

3.  Phytosynthesis of Nanoscale Materials

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Musa balbisiana

Ag

50 20 50

Spherical Triangular cuboidal

Banerjee et al. (2014)

Torreya nucifera

Au

10–125

Spherical

Kalpana et al. (2014)

Piper nigrum

Ag

7–50

Spherical, irregular

Paulkumar et al. (2014)

Hibiscus sabdariffa

Ag

20–90

Spherical

Sun et al. (2014)

Brassica rapa

Ag

5.7–24.4

Spherical

Narayanan and Park (2014)

Leucas martinicensis

Ag

20–30

Spherical

Ashokkumar et al. (2014)

Costus pictus

Ag

132.6

Spherical

Aruna et al. (2014)

Abutilon indicum

Ag Au

106 1–20

Spherical Spherical

Prathap et al. (2014) Mata et al. (2016)

Chenopodium ambrosioides

Ag

4–8.5

Irregular

Carrillo-López et al. (2014)

Eichhornia crassipes

ZnO

32–36 (SEM) 32 (TEM, XRD)

Spherical without aggregation

Vanathi et al. (2014)

Melia dubia

Ag

7.3

–

Kathiravan et al. (2014)

Suaeda monoica

Au

3.9–25.9

Spherical

Arockiya A-Rajathi et al. (2014)

Peunut

Au

110–130

Different shapes

Raju et al. (2014)

Capparis zeylanica

Cu

50–100

Cubic

Saranyaadevi et al. (2014)

Cymbopogon citratus

CuO Au

2.9 ± 0.64 20–50

Spherical Spherical, triangular, Hexagonal, rod

Brumbaugh et al. (2014) Murugan et al. (2015a)

Pelargonium zonale

Au

8–20

Pentagonal, triangular, spherical

Franco-Romano et al. (2014)

Solanum nigrum

Au ZnO

50 20–30 (XRD, EF–SEM) 29.79 (TEM)

Spherical Hexagonal Quasi-spherical

Muthuvel et al. (2014) Ramesh et al. (2015)

Sesbania grandiflora

Au ZnO Iron

7–34 15–35 25–60

Triangle, spherical Spherical Nonspherical

Das and Velusamy (2014) Rajendran and Sengodan (2017)

Nigella sativa

Ag

~15

Spherical

Amooaghaie et al. (2015)

88

Rod shape

Fu and Fu (2015)

1–90 and 10–80 65–184

Spherical Spherical, uniform

Reddy et al. (2015) Heera et al. (2015)

Plectranthus amboinicus ZnO Gymnema sylvestre

Au and Ag CuO



61

4  Plant-Mediated Synthesis of Metal NPs

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Salix alba

Au

63 (AFM) 50–80 (SEM) 29–35

–

Islam et al. (2015b)

Pongamia pinnata

ZnO

26 (XRD) 100 (DLS, SEM, TEM)

Spherical, hexagonal, nanorod

Sundrarajan et al. (2015)

Spathodea campanulata

ZnO

20–50

Spherical

Ochieng et al. (2015)

Anisochilus carnosus

ZnO

20–50

Hexagonal, spherical

Anbuvannan et al. (2015)

Phyllanthus niruri

ZnO

25.61

Hexagonal wurtzite, quasi-spherical

Anbuvannan et al. (2015)

Myrica nagi

Ag

50–69

Uniform

Bahuguna et al. (2015)

Euphorbia prostrata

Ag TiO2

12 ± 2.5 81.7–84.7

Spherical Spherical

Zahir and Indira (2015)

Eucalyptus oleosa

Ag

4–60

Spherical

Mo et al. (2015) and Pourmortazavi et al. (2015)

Butea monosperma

Au and Ag

10–100

Spherical, triangular, hexagonal

Patra et al. (2015)

Prunus yedoensis

Ag

20–70

Spherical, oval

Velmurugan et al. (2015)

Ziziphora tenuior

Ag

8–40

Spherical, uniformly

Sadeghi and Gholamhoseinpoor (2015)

Gloriosa superba

CuO

5–10

Spherical

Naika et al. (2015)

Cassia didymobotyra

Ag

18

Spherical

Akhtar and Swamy (2015)

Nepenthes khasiana

Au

50–100

Triangular, spherical

Bhau et al. (2015)

Zizyphus mauritiana

Au

24–40

Spherical

Sadeghi (2015)

Aspalathus linearis

Co3O4

2–7

Quasi-spherical

Diallo et al. (2015)

Albizia lebbeck

CuO

<100

Spherical

Jayakumarai et al. (2015)

Malva sylvestris

CuO

5–30

Spherical

Awwad et al. (2015)

Lawsonia inermis Gardenia jasminoides

Fe

21 32

Hexagonal

Naseem and Farrukh (2015)

Pyrus pyrifolia

CuO ZnO

24 22

Spherical Wurtzite hexagonal

Sundaramurthy and Parthiban (2015) Parthibana and Sundaramurthy (2015)

Ginkgo biloba

Cu Au

15–20 10–40

Spherical Global

Nasrollahzadeh and Mohammad Sajadi (2015) Zha et al. (2017)

Continued

62

3.  Phytosynthesis of Nanoscale Materials

TABLE 1  Biosynthesis of Nanoparticles Using Leaf Extracts—cont’d Plant

Metal

Size (nm)

Shape

Reference

Aloysia triphylla

Ag

5–40

Spherical

Luis López-Miranda et al. (2016)

Capparis spinose

Ag

5–30

Spherical

Benakashani et al. (2016)

Cassia roxburghii

Ag

25–35

Spherical

Balashanmugam et al. (2016)

Leucas lavandulifolia

Selenium

56–75

Spherical

Kirupagaran et al. (2016)

Arevalanata

CuO

40–100

Spherical, uniform

Hariprasad et al. (2016)

Elaise guineensis

Au

27.9±14.6

Spherical

Ahmad et al. (2016)

Ixora coccinea

ZnO

78–145

Spherical

Yedurkar et al. (2016)

Pinus desiflora

Ag

15–500

Cubic

Kumar et al. (2016b)

Panax ginseng

Au and Ag

10–20 and 5–15

Spherical

Singh et al. (2016c)

Aloe barbadensis

ZnO

8–20

Spherical, oval, hexagonal

Ali et al. (2016)

Erigeron bonariensis

Ag

13

Spherical

Kumar et al. (2016a)

Argemone maxicana

Ag

16–40

Crystalline

Siva et al. (2016)

Mirabilis jalapa

Ag

–

–

Asha et al. (2017)

Artemisia vulgaris

Au

50–100

Spherical, triangular, hexagonal

Sundararajan and Ranjitha Kumari (2017)

Nerium indicum

CuO

30–70

Uniform

Kashif et al. (2017)

20

Hexagonal

Kavitha et al. (2017)

Andrographis paniculata ZnO Parthenium

ZnO

23–90

Spherical, hexagonal

Agarwal et al. (2017)

Tinospora cordifolia

Ag

~30

Spherical

Selvam et al. (2017)

Passiflora caerulea

ZnO

30–50

–

Santhoshkumar et al. (2017)

Filicium decipiens

Pd

2–22

Spherical

Sharmila et al. (2017)

Conocarpus erectus

CuO

30–70

Uniform

Kashif et al. (2017)

Chenopodium murale

Au

11 and 14

–

Abdelghany et al. (2017)

Saraca indica

CuO

40–70

Spherical

Prasad et al. (2017)

Cinnamomum pedunculatum

Cu

80–500

Amorphous, spherical

Wang and An (2017)



63

4  Plant-Mediated Synthesis of Metal NPs

TABLE 2  Synthesis of Metals Nanoparticles Using Bark Extract of Different Plants Plant

Metal

Size (nm)

Shape

Reference

Cinnamon zeylanicum

Ag

30–150

Quasi-spherical, rod

Munnaluri et al. (2015) and Sathishkumar et al. (2009b)

Cinnamon zeylanicum

Pd

15–20

Uniform, Spherical

Sathishkumar et al. (2009a)

Shorea tumbuggaia

Ag

–

Spherical

Venkateswarlu et al. (2010)

Boswellia ovalifoliolata

Ag

30–40

Spherical

Ankanna et al. (2010)

Cassia fistula

Au

55.2–98.4

Different shapes

Daisy and Saipriya (2012)

Pinus eldarica

Ag

10–40

Spherical

Iravani and Zolfaghari (2013)

Leucas aspera

Ag

29–45

Spherical

Antony et al. (2013)

Saraca indica

Au

15–23

Triangular, pentagonal, hexagonal, spherical

Dash et al. (2014)

Eucommia ulmoides

Au

18.2

Spherical

Guo et al. (2015)

Afzelia quanzensis

Ag

10–80 (SEM) 19.8 (XRD)

Spherical

Moyo et al. (2015)

Pongamia pinnata

Ag

5–15 (small) 22–55 (large)

Spherical

Rajeshkumar (2016)

Salix alba

Ag

29–35 (HRTEM) 30–50 (AFM)

Spherical

Majeed and Khanday (2016)

Mimusops elengi

Au

9–14 (HRTEM) 3–20 (TEM)

Spherical

Majumdar et al. (2016)

Boswellia ovalifoliolata

ZnO

20.3

Spherical

Supraja et al. (2016)

Terminalia arjuna

Au Pt TiO2

7.18 8.41 6.46

Near spherical

Gopinath et al. (2016)

Cinnamomum verum

ZnO

61.90

Spherical, irregular

Padalia et al. (2017)

Alchornea laxiflora

Pt

3.68–8.77

–

Olajire et al. (2017)

Pterocarpus santalinus

Au

13–26

Spherical

Keshavamurthy et al. (2018)

Holarrhena antidysenterica

Ag

32

Spherical

Kumar et al. (2018)

Bauhinia variegata

Ag

50

Irregular spherical

Vaghela et al. (2017)

Butea monosperma

Ag

∼35 nm (HRTEM) ∼98 (DLS)

Nearly spherical

Pattanayak et al. (2017)

Prosopis juliflora

Ag

∼10–50 (SEM) ∼55 (DLS)

Spherical

Arya et al. (2018)

64

3.  Phytosynthesis of Nanoscale Materials

TABLE 3  Synthesis of Metals Nanoparticles by Stem Extract and Stem Latex of Various Plant Species Plant

Metal

Size (nm)

Shape

Reference

Citrullus colocynthis

Ag

75

Spherical

Kaliamurthi et al. (2011)

Euphorbia nivulia

Ag and Cu

5–10

Spherical

Valodkar et al. (2011)

Callicarpa maingayi

Ag

12.40 ± 3.27

Crystalline, cubic

Kamyar et al. (2012)

Calotropis procera

Ag

26–38

Spherical

Gondwal and Pant (2013)

Cissus quadrangularis

Ag

–

Spherical

Vanaja et al. (2013)

Hibiscus cannabinus

Ag Au

3–31 5–20

Spherical Spherical

Bindhu et al. (2014)

Piper nigrum

Ag

9–30

Spherical, irregular

Paulkumar et al. (2014)

Terminalia tomentosa

Ag

5–50

Hexagonal, pentagonal, spherical

Shah et al. (2014)

Ficus sycomorus

Ag

≤100

Spherical, irregular

Salem et al. (2014)

Artocarpus elasticus

Ag

5–20

Spherical

Abdullah et al. (2015)

Zingiber officinale

Cu and lead

3

Spherical, uniform

Delma et al. (2016)

Phyllanthus embilica

ZnO

26

Wurtzite hexagonal

Joel and Sheik Muhideen Badhusha (2016)

Leucas lavandulifolia

Selenium

56–75

Spherical

Kirupagaran et al. (2016)

Saccharum officinarum

Ag

10–60

Spherical

Kanniah et al. (2017)

Euphorbia confinalis

Ag

–

Spherical

Muchanyereyi et al. (2017)

Matricaria recutita

Ag

11

Quasi-spherical

Uddin et al. (2017)

Euphorbia antiquorum

Ag

10–50

Spherical

Rajkuberan et al. (2017)

4.4  Rhizome Extract Rhizome extract of Zingiber officinale, which acts as both a reducing and a stabilizing agent, was used for the synthesis of AuNPs with a particle size ranging from 5 to 15 nm by Kumar et al. (2011). The particles were highly stable at physiological condition compared to citrate capped NPs (Kumar et al., 2011). Karuppaiya et al. (2013) reported that the aqueous extract of Dysosma pleiantha rhizome was able to biosynthesize spherical AuNPs with an average of 127 nm within 20 min. The biosynthesized AuNPs were nontoxic to cell proliferation and also they could inhibit the chemo-attractant cell migration of human fibrosarcoma cancer cell line HT-1080 by interfering with the actin polymerization pathway (Karuppaiya et al., 2013). Nagajyothi reported the synthesis of spherical and rod shaped ZnO NPs in the range of 2.90–25.20 nm using Coptidis Rhizoma. They demonstrated the role of primary and secondary amine, aromatic and aliphatic amine, alcohol, carboxylic acid, alkyl halide, alkynes in the formation of ZnO NPs (Nagajyothi et al., 2014). The list of species that have been used to synthesize metals nanoparticles by Rhizome extract were shown in Table 4.



65

4  Plant-Mediated Synthesis of Metal NPs

TABLE 4  Metals Nanoparticles Formed in Rhizome Extract in Various Plant Species Plant

Metal

Size (nm)

Shape

Reference

Zingiber officinale

Au

5–15

Spherical

Kumar et al. (2011)

Dioscorea oppositifolia

Ag

>100 (DLS) 14 (TEM)

Spherical

Maheswari et al. (2012)

Dysosma pleiantha

Au

127

Spherical

Karuppaiya et al. (2013)

Gloriosa superba

Ag

63–70

–

Alagar Yadav et al. (2013)

Coptidis

ZnO

2.90–25.20

Spherical, rod

Nagajyothi et al. (2014)

Acorus calamus

Ag Au

31.83 15 and 20 (XRD) 100–500 (SEM)

Spherical Spherical

Nakkala et al. (2014)) Ganesan and Gurumallesh Prabu (2015)

Alpinia galangal

Ag

–

Spherical

Alyza and Norhidayah (2015)

Zingiber officinale

Ag and Fe3O4

5–25 (Ag) 1–3 (Fe3O4)

Crystalline

Ivashchenko et al. (2017)

4.5  Flower Extract Babu and Prabu (2011) described a green procedure for the synthesis of AgNPs using the Calotropis procera flower extract at room temperature. The synthesized AgNPs were stable up to 30 days and the size of the NPs was calculated as 35 nm (Babu and Prabu, 2011). Crocus sativus (saffron) extract was used for the synthesis of predominantly monodisperse AuNPs at room temperature within 24 h with an average size of 15 nm, by Vijayakumar et al. (2011). The HR-TEM images showed that AuNPs presented variable shapes, most of them spherical and triangular shape. They reported that the internal conversion mechanism of ketone group to carboxylic acid in flavonoids and the conversion of CO group of terpenes to C(O)O group in the extract of saffron may be involved in the Au3+ ion reduction (Vijayakumar et al., 2011). Mittal et al. (2012) described the biosynthesis of stable and monodisperse AgNPs (range of 25–40 nm) using Rhododendron dauricum flower extract. The synthesized NPs had antioxidant activity due to capped phenolic compounds that could be used against deleterious effects of free radicals (Mittal et al., 2012). The presence of flavonoids, terpenoids, and glycosides in the flower extract of Chrysanthemum indicum in bioreduction of silver ions to AgNPs was reported by Arokiyaraj et al. (2014) at room temperature within 2 min. The size and morphology of the particles were characterized by TEM, which showed spherical shapes and sizes that ranged between 37 and 72 nm (Arokiyaraj et al., 2014). Flower extract of Nyctanthes arbor-tristis was used by Jamdagni et al. (2018), as the biological reduction agent for synthesizing of ZnO NPs from zinc acetate dihydrate. Synthesis conditions were optimized for maximal and narrow size range synthesis of ZnO NPs. The size range of NPs obtained upon synthesis at optimum conditions determined by TEM was 12–32 nm. The NPs were tested for their antifungal potential and were found to be active against all five tested phytopathogens with lowest MIC value recorded as 16 μg/mL (Jamdagni et al., 2018). Metal nanoparticles were synthesized by flower extract using various plants are given in Table 5.

66

3.  Phytosynthesis of Nanoscale Materials

TABLE 5  Different Types of Flower Extract of Various Plants Used for the Synthesis of Metal Nanoparticles Plant

Metal

Size (nm)

Shape

Reference

Mirabilis jalapa

Au

∼100

Spherical

Vankar and Bajpai (2010)

Calotropis procera

Ag

35

Cubical

Babu and Prabu (2011)

Crocus sativus

Au

15

Spherical, triangular

Vijayakumar et al. (2011)

Nyctanthes arbortristis

Au Ag ZnO

19.8 ± 5.0 5–20 12–32

Spherical Oval, spherical Hexagonal

Das et al. (2011) and Gogoi et al. (2015)). Jamdagni et al. (2018)

Caesalpinia pulcherrima

Au

10–50

Spherical

Basavegowda et al. (2012a)

Rhododendron dauricum

Ag

25–40

Spherical

Mittal et al. (2012)

Helianthus annuus

Au

30–50

Spherical

Liny et al. (2012)

Pseudocydonia sinensis

Ag

15–20

Spherical, irregular

Nagajyothi et al. (2012)

Carthamus tinctorius

Au

40–200

Triangle, spherical

Basavegowda et al. (2012a)

Plumeria alba

Au

20–30 and 80–150

Spherical

Nagaraj et al. (2013)

Ipomoea indica

Ag

10–50

Crystalline

Pavani et al. (2013)

Millingtonia hortensis

Ag

10–30

Spherical, rod

Gnanajobitha et al. (2013c)

Moringa oleifera

Ag

14

Spherical

Bindhu et al. (2013)

Chrysanthemum indicum

Ag

37–72

Spherical

Arokiyaraj et al. (2014)

Rosa indica

Au

23.5–60.8

Spherical

Manikandan et al. (2015)

Tagetes erecta

Ag

10–90

Spherical, hexagonal, Padalia et al. (2015) irregular

Hibiscus sabdariffa

CeO2

∼3.9

–

Thovhogi et al. (2015)

Aloe vera

Cu

20–30

Versatile, spherical

Ppn et al. (2015)

Anthemis nobilis

CuO

18–61

–

Nasrollahzadeh et al. (2015)

Trifolium pretense

ZnO

60–70

–

Dobrucka and Długaszewska (2016)

Osmanthus fragrans

Ag

2–30

Spherical

Dong et al. (2016)

Hibiscus sabdariffa

Ag CdO

20–30 113 (HRSEM) 23–35 (HRTEM)

Spherical Cuboid

Dong et al. (2016) Thovhogi et al. (2016)

Pandanus odorifer Forssk

Ag

24–55

Quasi-spherical

Gupta and Chauhan (2017)

Cassia auriculata

Ag

10–35

Spherical, triangle

Muthu and Priya (2017)

Hydrangea paniculata

Ag and Mg

Mg: 56–107 Ag: 36–75

Spherical, ellipsoidal Karunakaran et al. (2017)

Aglaia elaeagnoidea

CuO

36–54

Spherical

Manjari et al. (2017)



4  Plant-Mediated Synthesis of Metal NPs

67

4.6  Fruit Extract Green biosynthesis of AuNPs and AgNPs using fruit extract of Emblica officinalis was reported by Ankamwar et al. (2005a,b). TEM analysis of the produced Au and Ag NPs indicated that they ranged in size from 15 to 25 nm and 10 to 20 nm, respectively (Ankamwar et  al., 2005b). A rapid synthesis of AgNPs using methanol extract of Solanum xanthocarpum berries as a reducing and capping agent was reported by Amin et al. (2012) during a 25 min process at 45°C. The NPs were found to be about 10 nm in size, mono-dispersed in nature, and spherical in shape. The synthesized Ag nanomaterials exhibited anti-H. pylori and urease inhibitory activities (Amin et  al., 2012). The triangular and hexagonal Ag NPs (1–50 nm in size) produced by using a pine cone extract within 2 min of incubation was reported by Velmurugan et  al. (2012). The nanohexagonal and nanotriangular NPs appeared to grow by a process involving rapid reduction with assembly at room temperature at a high pH. The formed Ag NPs demonstrated significant antibacterial action on both gram-positive and gram-negative agricultural pathogenic bacteria (Velmurugan et al., 2012). A green synthesis and stabilization of AgNPs using water extract of Terminalia chebula fruit was reported by Edison and Sethuraman (2012). In the neutral pH, the stability of AgNPs was found to be high. The size of Ag NPs was approximately 25 nm with good catalytic activity on reduction of methylene blue (Edison and Sethuraman, 2012). Synthesis of AgNPs of 10–15 nm size at room temperature using Syzygium cumini fruit extract was reported by Mittal et  al. (2014). Flavonoids present in S. cumini were found to be mainly responsible for the reduction and the stabilization of NPs. The NPs were also found to be able to destroy Dalton lymphoma cell lines under in vitro conditions (Mittal et al., 2014). The synthesis of spherical ZnO NPs (>20 nm) using fruit extract of Artocarpus gomezianus was reported by Suresh et al. (2015). The ZnO NPs exhibited potential photocatalytic activity towards the degradation of methylene blue and was found to have considerable antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals (Suresh et al., 2015). Shende et al. (2015) demonstrated the synthesis of CuNPs (an average size of CuNP 20 nm) using Citron juice (Citrus medica Linn.). CuNPs showed activity against the plant pathogenic fungi, such as F. oxysporum, C. lunata, A. alternata, and P. destructive and in vitro antimicrobial activity against Staphylococcus aureus, Proteus vulgaris, B. subtilis, K. pneumoniae, E. coli, and P. aeruginosa (Shende et  al., 2015). Ndikau et  al. (2017) reported the synthesis of AgNPs ­(average size 17.96 nm) using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were found: temperature of 80°C, pH 10, AgNO3 concentration 0.001 M, watermelon rind extract concentration 250 g/L (Ndikau et al., 2017). Table 6 shows the green synthesis of metal nanoparticles isolated from fruit extract of various plants.

4.7  Peel Extract Musa paradisiacal peels, which are inherently rich in polymers such as lignin, hemicellulose, and pectins, can be used in the synthesis of AgNPs. Boiled, crushed, acetone precipitated, air-dried banana peel powder was used for reducing silver nitrate to AgNPs (20 nm) by Bankar et al. (2010a,b) within 3 min of incubation at pH 3. The produced AgNPs displayed antibacterial and antifungal activities (Bankar et al., 2010b). Sugar beet pulp of Beta vulgaris

68

3.  Phytosynthesis of Nanoscale Materials

TABLE 6  Plant Mediated Synthesis of Metal Nanoparticles by Fruit Extract Plant

Metal

Size (nm)

Shape

Reference

Emblica officinalis

Au and Ag

15–25 and 10–20

–

Ankamwar et al. (2005b)

Caria papaya

Ag

15

Spherical

Jain et al. (2009)

Tanacetum vulgare

Au and Ag

10–40

Spherical, triangular

Dubey et al. (2010)

Pyrus pear

Au

200–500

Hexagonal, triangular

Ghodake et al. (2010)

Tribulus terrestris

Ag

16–28

Spherical

Gopinath et al. (2012)

Solanum xanthocarpum

Ag

10

Spherical

Amin et al. (2012)

Pine cone

Ag

1–50

Triangular, hexagonal

Velmurugan et al. (2012)

Vitis vinifera

Ag

30–40

Spherical

Gnanajobitha et al. (2013a)

Terminalia chebula

FeO Pd Au Ag

80 100 14–60 25

Amorphous Cubic Triangles, hexagons, and pentagons

Mohan Kumar et al. (2013a,b) Edison and Sethuraman (2012)

Dillenia indica

Ag

11–24

Spherical

Singh et al. (2013b)

Millingtonia hortensis

Ag

30–40

Spherical

Gnanajobitha et al. (2013b)

Terminalia arjuna

Au

60

Spherical

Mohan Kumar et al. (2013b)

Lycopersicon esculentum Ag

10–40

Spherical

Maiti et al. (2014)

Ag

10–50

Spherical

Mittal et al. (2014)

Crataegus douglasii

Ag

29

Spherical

Ghaffari-Moghaddam and Hadi-Dabanlou (2014)

Apples and oranges

Ag

10–300

Spherical, sharp corners Ærøe Hyllested et al. (2015)

Passiflora tripartita

Ag

49.7 ± 24.6

Spherical

Kumar et al. (2015b)

Lantana camara

Ag

75.2

Spherical

Kumar et al. (2015a)

Solanum trilobatum

Ag

12.50–41.90

Spherical

Ramar et al. (2015))

Rubus glaucus

CuO

43.3

Spherical

Sharma et al. (2015)

Sambucus nigra

Ag

20–80

Spherical

David et al. (2014)

Sambucus nigra

Ag

26

Spherical

Moldovan et al. (2016)

Rosa canina

ZnO

Spherical

Jafarirad et al. (2016)

Cucumis melo

Ag

13–25

-

Gul et al. (2016)

Citrullus lanatus

Ag

17.96

Spherical

Ndikau et al. (2017)

Lycium barbarum

Ag

3–15

Spherical

Dong et al. (2017)

Rosa sahandina

CuO and ZnO

<50

Spherical

Nagajyothi et al. (2017)

Litsea cubeba

SnO2

30

Irregular

Hong and Jiang (2017)

Forsythiae fructus

Y2O3

∼11

Flower

Nagajyothi et al. (2018)

Syzygium cumini Hovenia dulcis



4  Plant-Mediated Synthesis of Metal NPs

69

was used as a reducing and capping agent for the synthesis of gold nanowires and spherical, rod shaped AuNPs at room temperature within 5 h by Castro et al. (2011). Polysaccharides and proteins were found to be involved in the bioreduction and synthesis of NPs (Castro et al., 2011). Biosynthesis of AgNPs was achieved by Citrus sinensis peel extract by Kaviya et al. (2011). The AgNPs were spherical in shape and 35 and 10 nm in size at 25°C and 60°C, respectively (Kaviya et al., 2011). Roopan et al. (2012a,b) indicated that the spherical Pd NPs can be achieved from Annona squamosa L aqueous peel extract. FTIR analysis showed that aqueous extract contained the compounds having aldehyde and hydroxyl as a functional groups in the structure. They reported that the compounds containing –OH as a functional group play a critical role in capping the NPs (Roopan et  al., 2012a). Rapid synthesis of monodispersed AuNPs was reported by Ganeshkumar et al. (2013) by mixing gold solution with fruit peel extract of Punica granutum without using any surfactant or external energy within 60 s. The size distribution of AuNPs determined by TEM was 70.90 ± 8.42 nm. The FTIR result clearly showed that phenolic hydroxyls (OH band) and aromatic ring present in the extract act as the functional groups in capping the NPs (Ganeshkumar et  al., 2013). Krishnaswamy et  al. reported the synthesis of AuNPs ranging from 20 to 25 nm using grape waste. The growth of AuNPs was instantaneous, within 5 min, and the NPs were found to be highly stabilized. The waste management represents an important challenge in the agri-food-based industries and demands an integrated approach in the context of recycling, reuse, and recovery (Krishnaswamy et al., 2014). Yuvakkumar et al. (2014) demonstrated biosynthesis of ZnO and NiO nanocrystals via zinc- and nickel-ellagate complex formation using Nephelium lappaceum peel waste. The treated cotton fabric exhibited strong antibacterial activity due to the increasing ZnO nanocrystals adsorption on the surface of cellulosic fibers (Yuvakkumar et al., 2014). Table 7 includes all studies to date of peel extracts of different plants used for the synthesis of metal nanoparticles.

4.8  Seed Extract The synthesis of AgNPs was reported by Bar et al. (2009a,b) using aqueous seed extract of Jatropha curcas. The AgNPs were spherical in shape with diameter ranging from 15 to 50 nm (Bar et al., 2009b). Lukman et al. (2011) reported the rapid synthesis of colloidal spherical NPs with diameters in the range of 5–51 nm by reacting aqueous AgNO3 with Medicago sativa seed exudates under nonphotomediated conditions. Pre-dilution of the exudate induced the formation of single-crystalline Ag nanoplates, forming hexagonal particles and nanotriangles with edge lengths of 86–108 nm, while pH adjusting to 11 resulted in monodisperse AgNPs with an average size of 12 nm (Lukman et al., 2011). Biosynthesis of spherical AgNPs (XRD: 17 nm and TEM: 12 nm) using aqueous seed extract of Macrotyloma uniflorum was reported by Vidhu et al. (2011). Jayaseelan et  al. (2013) described the synthesis of spherical AuNPs using seed aqueous extract of Abelmoschus esculentus. XRD and FESEM confirmed the size of NPs of 62 nm and 45–75 nm, respectively. The FTIR of seed extracts showed that OH acts in capping the NPs synthesis as a functional group (Jayaseelan et al., 2013). Nazar et al. (2018) reported synthesis of CuNPs using Punica granatum seeds extract from copper(II) chloride salt. The size of the CuNPs was in the range of 40–80 nm with semi-spherical shape and uniform distribution (Nazar et al., 2018). Table 8 lists some of the seed extracts of various plants employed for the synthesis of metal nanoparticles.

70

3.  Phytosynthesis of Nanoscale Materials

TABLE 7  Plant-Mediated Synthesis of Metal Nanoparticles Using Peel Extracts Plant

Metal

Size (nm)

Shape

Reference

Musa paradisiaca

Au Ag Pd

300 25 50

Micronetworks, triangles, hexagons Uniform –

Bankar et al. (2010b) Bankar et al. (2010b) Bankar et al. (2010a)

Citrus sinensis

Ag

10––35

Spherical

Kaviya et al. (2011)

Musa pudica

Ag

20

Spherical

Kumar et al. (2012b)

Annona squamosa

TiO2 Pd Ag

23 ± 2 80–100 20–60

Spherical Nanocrystalline Spherical

Roopan et al. (2012b) Roopan et al. (2012a) Gupta and Chauhan (2017)

Punica granatum

Ag Au Cu Cobalt oxide

5–15 70.9 ± 8.42 20–30 40–80

Nanorod – Spherical Uniform

Naheed et al. (2012) Ganeshkumar et al. (2013) Kaur et al. (2016) Bibi et al. (2017b)

Beta vulgaris

Ag

25–75

Spherical/ quasi-spherical

Parameshwaran et al. (2013)

Phyllanthus emblica

Ag

188

Spherical, cubic

Rosarin et al. (2013)

Brucea javanica

Ag

38

Spherical

Ghaffari-Moghaddam and Hadi-Dabanlou (2014)

Mangifera indica Linn

Au

6.03–18.01

Spherical

Yang et al. (2014)

Grape waste

Au

20–25

Spherical

Krishnaswamy et al. (2014)

Nephelium lappaceum

ZnO NiO

50 50

Uniform Uniform

Yuvakkumar et al. (2014) Yuvakkumar et al. (2014)

Plukenetia volubilis

Ag

2–15

Spherical

Kumar et al. (2017)

4.9  Root Extract Sharma et al. (2007) reported the reduction of gold ions by the root cells of the Sesbania plant resulting in the formation of AuNPs (6–20 nm) transported symplastically to the aerial parts or shoots. The nanoparticle-bearing biomatrix of Sesbania was found to have the ability to reduce a hazardous and toxic pollutant, aqueous 4-nitrophenol (Sharma et al., 2007). Ahmad et  al. (2010) reported the synthesis of AgNPs by the room-dried stem and root of Ocimum sanctum. The broth of the plant was used as a reducing agent for the synthesis of Ag NPs at room temperature. A Transmission Electron Microscopy study showed that the AgNPs were of sizes 10 ± 2 (Ahmad et al., 2010). AgNPs synthesizing by root extract of Morinda citrifolia was reported by Suman et al. (2013). The spherical AgNPs were in the range of 30–55 nm and exhibited significant cytotoxic effect on HeLa cell lines (Suman et al., 2013). An effective and rapid approach for the green synthesis of AgNPs using root extract of Erythrina indica was indicated by Rathi Sre et al. (2015). The produced AgNPs were found to be spherical in shape with size in the range of 20–118 nm. Excellent cytotoxic effect of AgNPs has been observed in both MCF-7 and HEP G2 cell lines. (Rathi Sre et al., 2015). Table 9 summarizes some of the reports pertaining to metal nanoparticles synthesis mediated by root extracts of various plants.



71

4  Plant-Mediated Synthesis of Metal NPs

TABLE 8  Metal Nanoparticles Synthesis Using Seed Extracts of Various Plant Species Plant

Metal

Size (nm)

Shape

Reference

Jatropha curcas

Ag

15–50

Spherical

Bar et al. (2009b)

Medicago sativa

Ag

5–51, 104, 108

Spherical, clusters, crystalline

Lukman et al. (2011)

Papaver somniferum

Ag

3.2–7.6 μm

Spherical

Vijayaraghavan et al. (2012)

Macrotyloma uniflorum

Au

14–17

Spherical

Aromal et al. (2012)

Trigonella foenum-graecum

Au

15 to 25

Pentagonal, spherical

Aswathy Aromal and Philip (2012)

Artocarpus heterophyllus

Ag

10

Irregular

Jagtap and Bapat (2013)

Abelmoschus esculentus

Au

45–75

Spherical

Jayaseelan et al. (2013)

Psoralea corylifolia

Ag

100–110

–

Sunita et al. (2014)

Argyreia nervosa

Ag

20–50

Roughly spherical

Thombre et al. (2014)

Cuminum cyminum

Au

5

Spherical

Shalaby (2015)

Pistacia atlantica

Ag

27

Spherical

Sadeghi et al. (2015b)

Peganum harmala

ZnO

40

High structural porosity

Fazlzadeh et al. (2017)

Punica granatum

Cu

40–80

Semi-spherical, uniform

Nazar et al. (2018)

Trachyspermum ammi

Ag

3–50

Spherical, rod, cubic

Chouhan et al. (2017)

TABLE 9  Root Extracts of Various Plants That Act as a Reducing Agent During the Green Synthesis of Metal Nanoparticles Plant

Metal

Size (nm)

Shape

Reference

Sesbania

Au

6–20

Uniformly spherical

Sharma et al. (2007)

Ocimum sanctum

Ag

10

Uniform

Ahmad et al. (2010)

Morinda citrifolia

Ag

30–55

Spherical

Suman et al. (2013)

Rumex hymenosepalus

Ag

2–40

Cubic, hexagonal

Rodríguez-León et al. (2013)

Onosma dichroantha

AgCl

5–65

Spherical

Nezamdoost et al. (2014)

Delphinium denudatum

Ag

≤85

Spherical

Suresh et al. (2014)

Desmodium gangeticum

Ni

20–30

Cubic

Sudhasree et al. (2015)

Euphorbia heteradena Jaub

TiO2

17–45

Spherical

Nasrollahzadeh and Sajadi (2015)

Erythrina indica

Ag

20–118

Spherical

Rathi Sre et al. (2015)

Diospyros paniculata

Ag

17

Cubic crystalline

Rao et al. (2016)

Panax ginseng

Au and Ag

10–30

Spherical

Singh et al. (2016b)

Coleus forskohlii

Ag and Au

5–18

Spherical

Naraginti et al. (2016)

Diospyros sylvatica

Ag

8–10

Crystalline

Pethakamsetty et al. (2017)

72

3.  Phytosynthesis of Nanoscale Materials

4.10  Latex and Latex Extract The latex of Euphorbia nivulia was used successfully by Valodkar et al. (2011) for synthesis of Ag and Cu NPs stabilized by peptides and terpenoids. They found that Euphol was responsible for the reduction of Ag and Cu ions. They reported that it is a powerful green inorganic biocide agent with a minimal in vitro toxicity for human cell lines (Valodkar et al., 2011). The stabilized AgNPs (10–20 nm) and TiO2 NPs (25–100 nm) were synthesized using the latex of Jatropha curcas as a reducing and capping agent by Bar et  al. (2009a,b) and Hudlikar et  al. (2012), respectively. The cyclic peptide curcacycline A (an octapeptide) and curcacycline B (a nonapeptide) was found to play a crucial role for the reduction of Ag+ to Ag and stabilizing Ag NPs (Bar et al., 2009a; Hudlikar et al., 2012). Curcain (enzyme) and cyclic peptides (namely curcacycline A [an octapeptide] and curcacycline B [a nonapeptide]) were identified as possible reducing and capping agents present in the latex of J. curcas L. There were two broad categories of NPs: the first have diameters from 25 to 50 nm and were mostly spherical in shape; the second had larger and uneven shapes (Hudlikar et al., 2012). Latex and latex extracts from different plants used for the synthesis of metal nanoparticles were shown in Table 10.

4.11  Gum and Gum Extract Biosynthesis of AgNPs from silver nitrate using gum kondagogu (Cochlospermum gossypium) as a reducing and stabilizing agent was reported by Kora et al. (2010). The monodispersed and spherical AgNPs with size of around 3 nm were achieved after optimizing the reaction conditions (Kora et  al., 2010). The synthesis and stabilization of colloidal Ag, Au, and Pt NPs was accomplished by Vinod et al. (2011) in an aqueous medium containing gum Cochlospermum gossypium. The Ag and Au NPs had average sizes of 5.5 ± 2.5 and 7.8 ± 2.3 nm, respectively, while the Pt NPs had an average size of 2.4 ± 0.7 nm. The reaction between HAuCl4 and –OH groups present in the gum kondagogu indicated that the reduction of Au (III) to Au (0) occurs through oxidation of hydroxyl to the carbonyl group and the presence of amino acid is the key factor for the formation of Pt NPs within the gum kondagogu matrix (Vinod et al., 2011). Gum of acacia was used by Venkatesham et al. (2012) as both a reducing and a stabilizing agent for synthesizing stable AgNPs. This reaction was carried out in an autoclave at a pressure of 15 psi and a temperature of 120°C for 2 min (Venkatesham et al., 2012). In ­addition, TABLE 10  Plant-Mediated Synthesis of Metal Nanoparticles Using Latex and Latex Extracts Plant

Metal

Size (nm)

Shape

Reference

Jatropha curcas

Ag Lead TiO2 ZnS

10–20 10–12.5 25–100 10

Cubic Spherical – Spherical

Bar et al. (2009a) Joglekar et al. (2011) Hudlikar et al. (2012) Hudlikar et al. (2012)

Euphorbia nivulia

Ag and Cu

5–10

–

Valodkar et al. (2011)

Euphorbia milii

Ag

10–50

Spherical

de Matos et al. (2011)

Thevetia peruviana

Ag

10–30

Spherical

Rupiasih et al. (2015)



4  Plant-Mediated Synthesis of Metal NPs

73

TABLE 11  Green Synthesis of Metal Nanoparticles Using Gum and Gum Extracts of Different Plants Plant

Metal

Size (nm)

Shape

Reference

Cochlospermum gossypium

Ag Au Pt

5.5 ± 2.5 7.8 ± 2.3 2.4 ± 0.7

Spherical Spherical Spherical

Vinod et al. (2011), Kora et al. (2010) Vinod et al. (2011)

Astragalus gummifer

Ag

13

Spherical

Kora and Arunachalam (2012)

Anogeissus latifolia

Ag

5.7

Spherical

Kora et al. (2012)

Boswellia serrata

Ag

7.5 ± 3.8

Spherical

Kora et al. (2012)

Karaya gum

CuO

4.8–7.8

Spherical

Padil and Černík (2013)

Acacia nilotica

Ag

10–40

Spherical

Mane Gavade et al. (2016)

Azadirachta indica

ZnO

13–15 (XRD) 30–60 (FESEM)

Flower shape, Spherical

Geetha et al. (2016)

Acacia senegal (Arabic gum)

Au

3.9–8.8

Spherical

Shalaby (2015)

Kora et  al. (2012) demonstrated the biosynthesis of monodispersed and spherical AgNPs (with size around 5.7 ± 0.2 nm) using gum ghatti (Anogeissus latifolia). FTIR analysis indicated that both hydroxyl and carbonyl groups of gum were involved in the synthesis of AgNPs (Kora et al., 2012). Table 11 lists metal nanoparticles synthesized using gum and gum extracts of different plants.

4.12  Plant Extract and Aqueous Extract Wang et al. (2009) reported the extracellular synthesis of well-dispersed AuNPs with the size ranged in 5–30 nm using Scutellaria barbata (dried whole plant) as the reducing agent (Wang et al., 2009). Das et al. reported the biosynthesis of AgNPs by ethanolic extract of Phytolacca decandra (90 nm, Spherical), Hydrastis canadensis (111 nm, Spherical) and Thuja occidentalis (122 nm, Spherical) that showed differential cytotoxicity through G2/M arrest in A375 cells (Das et al., 2013). Green synthesis of AgNPs was demonstrated by Vijay Kumar et al. (2014) using Boerhaavia diffusa plant extract as a reducing agent. AgNPs were spherical in shape with average size of 25 nm. Islam et al. (2015a,b,c) indicated the synthesis of AuNPs by E. milii methanolic extract. The produced NPs showed enhanced stability in different NaCl and pH solutions. Moreover, the AuNPs improved the potency of E. milii methanolic extract and exhibited significant analgesic, muscle relaxant, and sedative properties (Islam et al., 2015c). The synthesis of copper NPs with aqueous extract of Psidium guajava L (guava) was recognized by Caroling et al. The formation of copper NPs was indicated by the color change from colorless to brown (Caroling et  al., 2015). Synthesis of ZnO NPs using Vitex negundo plant extract with zinc nitrate hexahydrate as precursor was demonstrated by Ambika et al. Presence of isoorientin (flavone) in V. negundo plant extract was found mainly responsible for the formation of ZnO NPs. Polyphenolic compound of Vitex negundo extract was determined as a hydrolytic agent. ZnO NPs synthesized by V. negundo leaf and flower showed similar size of 38.17 nm confirmed by XRD analysis (Ambika and Sundrarajan, 2015).

74

3.  Phytosynthesis of Nanoscale Materials

4.13  Other Tissues of Plants and Living Plant Systems Gardea-Torresdey et al. (2002, 2003) confirmed that living alfalfa plants have the ability to uptake gold and silver from solid media and biosynthesize icosahedral-shaped AuNPs with size ranging between 6 and 10 nm. Dark field image TEM showed the connection of AgNPs of different sizes by possibly noncrystalline silver atomic wires (Gardea-Torresdey et al., 2002, 2003). AgNPs were synthesized by using callus extract of Carica papaya by Mude et al. (2009). MS (Murashige & Skoog) medium supplemented with the growth hormones, 2.0 mg/L IBA and 0.5 mg/L BAP was found to be more suitable for the induction of callus and multiple shoots in papaya. SEM micrograph confirmed the synthesis of spherical AgNPs in the size range of 60–80 nm (Mude et  al., 2009). Raghunandan et  al. reported synthesis of irregular shaped stable AuNPs in the range of 5–100 nm using aqueous dried clove buds of Syzygium aromaticum solution. FTIR showed that the freely water soluble flavonoids of clove buds are responsible for bioreduction (Raghunandan et al., 2010). Tuber powder and tuber extract of Curcuma longa were found to have potential for synthesis of AgNPs extracellularly. Silver nanoparticle synthesis rate was higher in tuber extract compared to the powder form, which was attributed to the large and easy availability of the reducing agents in the extract. The minimum bactericidal concentration (MBC) for Escherichia coli BL-21 strain was found to be 50 mg/L (Sathishkumar et al., 2010). Sugar beet pulp was used as a reducing and capping agent for the synthesis of gold nanowires at room temperature by Castro et al., 2011. Ghosh et  al. (2012) reported on the rapid synthesis of AgNPs by reduction of aqueous AgNO3 solution at 50°C in 5 hours using D. bulbifera tuber extract. Varied morphology of the bioreduced AgNPs was included, such as spheres, triangles, and hexagons (Ghosh et al., 2012). In situ synthesis of ZnO nanorods on cellulosic chains of cotton fabric was accomplished using natural plant source namely Keliab and Zinc acetate. The crystal size of ZnO NPs was calculated to be around 13 nm by XRD (Aladpoosh and Montazer, 2015). Coccia et al. (2012) reported one-pot synthesis of spherical Pd NPs (16 nm to 20 nm) using lignin isolated from red pine (Pinus resinosa). AuNPs with hexagonal, pentagonal, and triangular shapes and sizes in the range of 4–22 nm were synthesized using Gymnocladus assamicus pod extract in aqueous medium by Tamuly et al. (2013). The formation of pure metallic NPs by reduction of the metal ions was possibly facilitated by reducing by phenolic acids like gallic acid, protocatechuic acid, and kaempferol present in the G. assamicus pod extract (Tamuly et al., 2013). The produced AgNPs were tested for antibacterial activity against three fish bacterial pathogens, Aeromonas hydrophila, Pseudomonas fluorescens, and Flavobacterium branchiophilum (Vijay Kumar et al., 2014). Islam et al. reported the rapid synthesis of AuNPs with the size in range of 20–200 nm using Pistacia integerrima galls extract. FTIR spectra confirmed the involvement of amines, amide groups, and alcohols in capping and reduction of AuNPs (Islam et al., 2015a). Cocos nucifera coir dust methanolic extract was utilized for the production of spherical lead NPs (PbNPs) by Elango and Roopan (2015). GC–MS analysis of methanolic extract showed the secondary metabolites can mainly act as reducing and capping agents for the formation of Pb-NPs. The results stated that the produced Pb-NPs size was 47 nm and with good activity against S. aureus and photocatalytic activity about malachite green (Elango and Roopan, 2015). Ghosh et al. (2016) reported the synthesis of AuNPs and AgNPs using



6  Biosynthesis of Metal Nanoparticles With Alga

75

Dioscorea oppositifolia tuber extract within 5 h. Spherical AuNPs ranging from 30 to 60 nm were also spotted. Similarly, distinctly spherical AgNPs without any agglomeration were observed with size ranging between 17 and 25 nm. AuNPs and AgNPs synthesized by D. oppositifolia tuber extract exhibited efficient catalytic activity towards reduction of 4-nitrophenol to 4-aminophenol by NaBH4 with pseudo-first order rate kinetics (Ghosh et al., 2016).

5  BIOSYNTHESIS OF BIMETALLIC NANOPARTICLES Rapid formation of stable spherical silver and triangular AuNPs at high concentrations using of Azadirachta indica leaf broth at 30 min was reported by Shankar et al. (2004). Competitive reduction of Au3+ and Ag+ ions present simultaneously in solution during exposure to Neem leaf extract leads to the synthesis of bimetallic Au core–Ag shell NPs in the solution. The particles are predominantly spherical in morphology; they were not well separated from each other and tend to form structures wherein large particles (dimensions in the range 50–70 nm) were capped with smaller particles (15–20 nm in diameter) (Shankar et  al., 2004). Diopyros kaki leaf extract was used by Song and Kim (2008) for the synthesis of bimetallic Au/Ag NPs within 1.5 h. SEM images showed that large Au/Ag particles of 50–500 nm were formed with some cubic structure, while pure Ag particles obtained by reduction of only Ag+ ion were smaller with diameter of 15–90 nm and predominantly spherical (Song and Kim, 2008). Au, Ag, Au–Ag alloy and Au core–Ag shell NPs were synthesized using the aqueous extract and dried powder of Anacardium occidentale leaf within 20 min. AuNPs were more stable at pH 6 while AgNPs shows maximum stability at pH 8. FTIR spectra of the water soluble showed polyols and proteins were responsible for the bioreduction of the Au/Ag ion. Sheny et  al. (2011) demonstrated the quantity of plant material was a key factor determining the formation and size distribution of NPs.

6  BIOSYNTHESIS OF METAL NANOPARTICLES WITH ALGA Algae are photosynthetic organisms that range from unicellular forms (e.g., Chlorella) to multicellular ones (e.g., Brown algae). Algae including photoautotrophic, eukaryotic, aquatic, and oxygenic microorganisms have the ability to accumulate heavy metals. Algae lack basic plant structures like roots and leaves (Castro et  al., 2013). Researchers are finding cleaner techniques for the preparation of NPs. This represents a good advantage of using algae as an abundant raw material source (Castro et al., 2013). The intracellular synthesis of AuNPs of dimensions 5–35 nm using alga Tetraselmis kochinensis was reported by Senapati et al. (2012). The particles were more concentrated upon the cell wall than on the cytoplasmic membrane, possibly due to reduction of the metal ions by enzymes present in the cell wall and cytoplasmic membrane (Senapati et al., 2012). Aqueous extract of Sargassum myriocystum was used by Stalin Dhas et al. (2012) for the biosynthesis of AuNPs within 15 min at 76°C. The produced AuNPs were stable, well defined, triangular and spherical, and crystalline with an average size of 15 nm (Stalin Dhas et al., 2012). Mahdavi et al. (2013) reported the rapid, single-step, and green biosynthetic method for the production of iron oxide nanoparticles (Fe3O4-NPs) by reduction of ferric chloride solution with Sargassum muticum water extract containing s­ ulfated

76

3.  Phytosynthesis of Nanoscale Materials

polysaccharides as a main factor, which acts as a reducing agent and efficient stabilizer. The hydroxyl, sulfate, and aldehyde group present in the Sargassum muticum extract were apparently involved in the bioreduction and stabilization of Fe3O4-NPs (average size of 18 ± 4 nm and cubic shapes) (Mahdavi et al., 2013). Au and AgNPs were biosynthesized using a simple method by Castro et al. (2013) with green alga Spyrogira insignis and red alga Chondrus crispus as reducing agents. TEM observations revealed that produced AuNPs by C. crispus at the acidic medium were triangular, hexagonal, and spherical (30–50 nm). They reported that C. crispus is rich in sulfur, which probably binds gold, and the extract may be responsible for the reduction and stabilization of AuNPs. TEM analysis indicated that they ranged in size from 30 nm with spherical shape. The huge amount of hydroxyl groups in the cell wall could act as reducing agent of silver cations (Castro et al., 2013). Biological synthesis of AuNPs using Sargassum swartzii within 5 min at 60°C was reported by Dhas et al. (2014). The AuNPs were stable, spherical in shape with well-defined dimensions, and the average size of the particles was 35 nm. The synthesized AuNPs exhibited a dose-dependent cytotoxicity against human cervical carcinoma (HeLa) cells and AuNPs induced cytotoxicity in term of mitochondrial damage (Dhas et al., 2014). The formation of uniform and quasi-spheres AgNPs (average size 17 nm) by the reduction of aqueous silver metal ions during exposure to both fresh and dry seaweed extracts of Spirogyra varians was reported by Salari et al. (2016). The FTIR spectra of S. varians aqueous extract and biosynthesized AgNPs indicated the presence of [NH]CO group, O–H stretch carboxylic, hydroxyl, carbonyl and amine groups (Salari et al., 2016). Kadukova (2016) investigated the behavior of the green freshwater alga Parachlorella kessleri in the presence of silver. The Ag+ ion concentration sharply decreased by 75% within the first 2 min and then equilibrium was reached by the dead P. kessleri biomass and in the presence of living P. kessleri cells a 68% decrease of silver concentration was observed within 24 h. Spherical AgNPs with an average size of 9 nm in experimental media was revealed by a TEM image. The presence of hydroxyl groups on the cell walls could be responsible for the formation of NPs (Kadukova, 2016). The cell-free extract of Chlamydomonas reinhardtii, a fresh water microalga, was used by Rao et al. (2016) to synthesize the ZnO nanoflowers and by Cheloni et al. (2016) to synthesize the CuO-nanoparticles (Cheloni et al., 2016; Rao and Gautam, 2016). The nanoflowers were composed of individual nanorods that assembled to form flower-like structures. The nanorods measured 330 nm in length and these nanorods were self-assembled to form porous nanosheets that were found to be 55–80 nm. The produced nanoflowers demonstrated the enhanced photocatalytic activity against methyl orange (MO) under natural sunlight. FTIR analysis suggested that algal biomolecules such as CO stretching, NH bending band of amide I and amide II, CO stretch of zinc acetate, and COC of polysaccharide were responsible for the synthesis and stabilization of ZnO nanostructures (Rao and Gautam, 2016). Stable AgNPs have been synthesized using an aqueous extract of Dunaliella salina, which acted as a reducing and stabilizing agent (Singh et al., 2017). TEM and AFM analyses confirmed the presence of spherical AgNPs with average size of 15.26 nm and the average surface roughness as 8.48 nm. A comparison of cancer (MCF7) and normal (MCF10A) cell lines after exposure to AgNPs and the anticancer drug (Cisplatin), clearly demonstrated that the produced AgNPs may be used as an anticancer agent (Singh et al., 2017). Table 12 lists some of the algae used for the synthesis of metal nanoparticles.



77

6  Biosynthesis of Metal Nanoparticles With Alga

TABLE 12  Metal Nanoparticles Synthesis Using Algae Algae

Metal

Size (nm)

Shape

Reference

Phaeodactylum tricornutum

CdS

–

–

Scarano and Morelli (2003)

Sargassum wightii

Au

8–12

Spherical

Singaravelu et al. (2007)

Fucus vesiculosus

Pb, Cu, Cd Au

– 6–50

– Spherical

Mata et al. (2008) Mata et al. (2009)

Porphyra vietnamensis

Ag

13±3

Spherical

Venkatpurwar and Pokharkar (2011)

Turbinaria conoides

Au Ag

1–100 15–25

Triangular, hexagonal, spherical Almost spherical

Vijayaraghavan et al. (2011) Aswathy Aromal and Philip (2012)

Stoechospermum marginatum

Au

18.7–93.7

Spherical, hexagonal, Arockiya Aarthi Rajathi et al. triangle (2012)

Tetraselmis kochinensis

Au

5–35

Spherical, triangular

Senapati et al. (2012)

15 36

Spherical, triangular Rectangle, triangle, hexagonal, rod, spherical

Stalin Dhas et al. (2012) Nagarajan and Arumugam Kuppusamy (2013) Rajiv et al. (2013)

Sargassum myriocystum Au ZnO

Sargassum muticum

Ag Fe3O4

5–15 18

Spherical Cubic shape

Azizi et al. (2013) Mahdavi et al. (2013)

Chondrus crispus

Au

30–50

Triangular, hexagonal, spherical

Castro et al. (2013)

Padina gymnospora

Au

53–67

Uniform

Singh et al. (2013a)

Codium capitatum

Ag

3–44

Spherical

Kannan et al. (2013)

Ecklonia cava

Au and Ag

30–50 43 (Ag)

Spherical, triangular

Castro et al. (2013) and Venkatesan et al. (2014)

Bifurcaria bifurcate

CuO

5–45

Prasiola crispa

Au

5–5

Spherical, cubic

Sharma et al. (2014)

Sargassum plagiophyllum

Ag

18–42 (HR–TEM) 21–48 (FESEM)

Spherical

Stalin Dhas et al. (2014)

Enteromorpha flexuosa

Ag

~15

Spherical

Yousefzadi et al. (2014)

Sargassum swartzii

Au

35

Spherical

Dhas et al. (2014)

Corallina officinalis

Au

14.6

Spherical

El-Kassas and El-Sheekh (2014)

Bifurcaria bifurcate

CuO

5–45

Spherical

Abboud et al. (2014)

Agathosma betulina

ZnO CdO

15 and 12–26 25 ~50

Spherical Cubic

Thema et al. (2015b) Thema et al. (2015a)

Abboud et al. (2014)

Continued

78

3.  Phytosynthesis of Nanoscale Materials

TABLE 12  Metal Nanoparticles Synthesis Using Algae—cont’d Algae

Metal

Size (nm)

Shape

Reference

Spirulina platensis

Au

20–30, ~5

Spherical

Uma Suganya et al. (2015)

Chlorococcum

Iron

20–50

Spherical

Subramaniyam et al. (2015)

Caulerpa racemosa

Ag

5–25

Spherical, triangular

Kathiraven et al. (2015)

Ulva reticulata

Ag

–

Spherical

Saraniya Devi and Bhimba (2014) and Shankar et al. (2016)

Spirogyra varians

Ag

17

Uniform, quasi-spheres

Salari et al. (2016)

Gracilaria birdiae

Ag

20.2–94.9

Spherical

de Aragão et al. (2016)

Parachlorella kessleri

Ag

9

Spherical

Kadukova (2016)

Pithophora oedogonia

Au

32

Spherical

Li and Zhang (2016)

Chlamydomonas reinhardtii

ZnO CuO

55–80 –

Nanoflower, rod –

Rao and Gautam (2016) Cheloni et al. (2016)

Dunaliella salina

Ag

15.26

Spherical

Singh et al. (2017)

Chlorella vulgaris

Pd

5–20

Spherical

Arsiya et al. (2017)

Laurencia catarinensis

Ag

39–77

Spherical, triangular, Abdel-Raouf et al. (2018) rectangle, polyhedral, hexagonal

4–24

Spherical

3.85–77.13

Spherical, rods, Abdel-Raouf et al. (2017) triangular, truncated triangular, hexagonal

Enteromorpha compressa Ag Galaxaura elongata

Au

Ramkumar et al. (2017)

7  METAL NANOPARTICLES CHARACTERIZATION In the case of biological synthesis of NPs, the aqueous metal ion precursors from metal salts are reduced and as a result a color change occurs in the reaction mixture. This is the first qualitative indication that NPs are being formed (Shah et al., 2015). NPs are generally characterized by their size, shape, surface area, and dispersity. The common techniques to evaluate NPs characteristics can be classified into two main groups, namely quantitative and qualitative. These methods include a range of various sophisticated techniques, such as UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), surface enhanced Raman spectroscopy (SERS), atomic force microscopy (AFM), high angle annular dark field (HAADF), atomic absorption spectroscopy (AAS), inductively coupled plasma (ICP), and X-ray photoelectron spectroscopy (XPS). After the reaction, NPs can be separated from the colloid by high-speed centrifugation and then examined using advanced nanocharacterization techniques (Shah et al., 2015).



7  Metal Nanoparticles Characterization

79

7.1  Qualitative Analysis Spectroscopy-based techniques such as UV-vis, DLS, XRD, EDS, FT-IR, and Raman are considered indirect methods of determining data related to composition, structure, crystal phase, and properties of NPs (Mohammadlou et al., 2016). 7.1.1  Color Changing of the Reaction Solution Usually the change in color of the aqueous salt solution of a metal is indicative of metal NPs formation. For example, distinct color change of the silver nitrate solution from colorless to gray color after the reduction process indicates the formation of AgNPs (Mohammadlou et al., 2016). The callus extract of the salt marsh plant, Sesuvium portulacastrum, shows gradual change in color to yellowish brown, with intensity increasing during the period of incubation with AgNO3 (Nabikhan et al., 2010). The properties of AuNPs are very different from those of bulk, as AuNPs are a wine red solution while the bulk gold is yellow solid (Noruzi, 2015). The color change also occurs when the size of the particles increases; in the case of gold it is from deep red to purple (Menon et al., 2017). For example, the aqueous gold ions when exposed to Pistacia integerrima galls extract were rapidly reduced as evident from abrupt color change to ruby red, suggesting the biosynthesis of AuNPs (Islam et al., 2015a). The reducing potential of Aloe barbadensis leaf extract has been exploited for biosynthesis of ZnONPs. Addition of leaf extract in increasing amounts to aqueous ZnSO4 solution resulted in the change in color from off white to yellowish brown to reddish brown, and finally to colloidal brown, indicating ZnONPs formation (Ali et al., 2016). The number of particles increased with increasing color and size of nanoparticles increasing when changing color from light color to dark color. For examples, the yellow color of gold chloride and Banana peel extract solution turned to brown, purplish-pink, ruby red and a dark reddish color developed when the reaction was carried out at pH 2–5 and increased size of AuNPs (Bankar et al., 2010b). In the AgNPs synthesis by banana peel extract, when the reaction was carried out at pH 3.0 with 0.125, 0.25, and 0.5 mM concentrations of silver nitrate, yellow, golden brown, and brown colors were observed, respectively. When the silver nitrate concentration ranged between 1.0 and 2.0 mM, darker shades of brown were observed (Bankar et al., 2010b). 7.1.2  UV-Visible Spectrophotometry The UV-visible spectroscopy covers the UV range between 190 and 380 nm and the visible range between 380 and 800 nm. Both types of radiation interact with matter and promote electronic transitions from the ground state to higher energy states (Kelly et al., 2003). Wavelengths between 300 and 800 nm are generally used for characterizing metallic NPs ranging in size from 2 nm up to around 100 nm (Mohammadlou et al., 2016). UV-vis spectroscopy is an important technique to determine the formation and stability of metal NPs in aqueous solution. In addition, UV-vis spectrophotometry is simple, fast, sensitive, and selective for different types of NPs (Rajeshkumar and Bharath, 2017). Both absorption wavelength and peak width increases as the particle size increases (Gogoi, 2013). After the change of the extract color to red or violet in the case of AuNPs, and brown in the case of AgNPs, the observation of an absorption band in the mentioned wavelength regions confirms the production of these NPs (Noruzi, 2015). The intensity of absorption band increases when the color change

80

3.  Phytosynthesis of Nanoscale Materials

from colorless to other colors is observed. Bankar et al. (2010a,b) reported the biosynthesis of AgNPs using banana peel extract at which dark brown color and characteristic peaks were observed in the reaction mixture at 80°C and 100°C. They reported a light brown color and less pronounced peaks at lower temperatures (40°C and 60°C). They concluded that the size of AgNPs decreases with the increase in temperature. At pH 2.0, there was neither a change in color nor a characteristic peak. A yellow color was observed at pH 2.5 and a dark brown color and an intense peak were observed at pH 3.0. The reaction mixtures turned into varying shades of brown at pH 3.5, 4.0, 4.5, and 5.0. At pH values greater than 5.0, a white precipitate was observed. A change in color was also associated with well-defined peaks characterized by maxima centered around 430 nm (Bankar et al., 2010b). Spectrophotometric absorption measurement in the wavelength ranging from 400 to 450 nm is used to characterize AgNPs (Poinern et al., 2013b), while AuNPs are generally detected by the presence of peaks between 500 and 550 nm (Kelly et al., 2003) and two absorption peaks at wavelengths of 402 and 415 nm indicate the formation of iron NPs (Mahdavi et al., 2013). The onset wavelength of the optical absorption for TiO2 NPs appears at 284 nm in UV-vis spectroscopy (Chen and Mao, 2007). 7.1.3  Surface Plasmon Resonance (SPR) The SPR band can give useful information about the size and shape of the synthesized NPs. When the particle size increased, the absorption peak shifted towards the red wavelength, which indicated the formation of larger-sized nanoparticles and the reduction in particle size leads to the decrease in maximum wavelength (blue shift). The variations in the SPR wavelength with the variations in particle size were reported in literature. The asymmetrical and broad SPR bands are indicative of the formation of anisotropic NPs. Moreover, the existence of a peak in the near infrared (NIR) region can be attributed to longitudinal SPR, which indicates anisotropy in the shape of the NPs as previously reported (Noruzi, 2015). The SPR band can give useful information about the size and shape of the synthesized nanoparticles. Increase in particle size causes increase in maximum wavelength (red shift), and reduction in particle size leads to decrease in maximum wavelength (blue shift) (Noruzi, 2015). 7.1.4  Scanning Electron Microscope (SEM) Scanning Electron Microscope is a technique that uses electrons instead of light to form an output image. SEM images include the formation of thin films of carbon coating on copper grids (Menon et al., 2017). The SEM images are capable of determining different particle shapes, surface morphology, sizes and size distributions of the synthesized NPs at the micro (10−6) and nano (10−9) scales (Rajeshkumar and Bharath, 2017). The SEM micrographs also indicate the purity and polydispersity of resulting metal NPs (Mohammadlou et al., 2016). 7.1.5  X-Ray Diffraction Analysis (XRD) XRD is a useful tool in obtaining information about the atomic structure of materials. XRD is not only used for qualitative identification of minerals in geological samples by the fingerprinting approach but it is also used for the quantification of mineralogical data (Mohammadlou et al., 2016). It is an analytical technique and is used to investigate the crystal or polycrystalline structures, to determine the quantitative resolution of chemical ­compounds,



7  Metal Nanoparticles Characterization

81

for the qualitative identification of various chemical species, and to measure the degree of crystallinity and particle sizes. Since every crystalline material has a special pattern of diffractions, the XRD technique can identify crystalline materials by comparing the obtained pattern with the reference library (Rajeshkumar and Bharath, 2017). The broadening of the peaks in XRD confirms the formation of particles in nano size (Noruzi, 2015). If the NPs are produced in an amorphous structure, no diffraction peak is observed and this technique cannot help to identify the sample (Menon et al., 2017; Noruzi, 2015). 7.1.6  Atomic Force Microscopy (AFM) AFM has emerged as an effective tool to image NPs, especially due to its ability to work on biological samples rich in water. The shape, size, and surface area of the synthesized NPs are studied using AFM (Mohammadlou et al., 2016). The AFM imaging is performed using ­phosphorus-doped silicon probes, while the sample is equipped by dissolving the bioreduced NPs in either ethanol or water, and then a droplet of the solution is added on the pre-cleaned substrate of silicon (Menon et  al., 2017). The improvement of AFM over conventional microscopes such as SEM and TEM is that AFM technique makes three-dimensional images so that particle height and volume can be intended (Mohammadlou et al., 2016). The number of particles analyzed by AFM is much smaller and thus DLS provides better size distribution and polydispersity index (Bhattacharjee, 2016). 7.1.7  Surface Enhanced Raman Spectroscopy (SERS) The Raman spectrum of the NPs solution is recorded to detect the possible functional groups of capping agents participating in stabilization of the NPs. Surface enhanced Raman spectroscopy is a popular technique in bioanalytical chemistry and a potentially powerful enabling technology for in vitro diagnostics. In fact, SERS combines the excellent chemical specificity of Raman spectroscopy with the good sensitivity provided by enhancement of the signal that is observed when the analyzed molecule lies over (or very close to) the surface of metal NPs. The modern modification of Raman spectroscopy utilizes generation of a very strong electromagnetic field resulting from exciting of the localized surface plasmons in the metallic NPs. SERS spectrum is observed if a molecule is in a close contact with a SERS-active support. Currently, SERS has been widely used in the detection, identification, and monitoring of various biochemical processes because it is fast, label-free, and noninvasive and has high molecular specificity and sensitivity. SERS provides valuable information on the adsorption mechanism of a (bio)molecule on a metallic surface by indicating which functional groups or atoms participate in metal–adsorbate interactions (Mohammadlou et al., 2016). 7.1.8  Energy Dispersive X-Ray Spectroscopy (EDX) EDS is a microanalysis method used in addition to SEM. EDX is a chemical analysis method that is used in combination with SEM to know the elemental composition of metal NPs samples (Menon et al., 2017). The EDS technique detects X-rays emitted from the sample when it is bombarded by an electron beam, and the EDS X-ray detector quantifies the relative abundance of the discharged X-rays compared with their energy (Rajeshkumar and Bharath, 2017). When the sample is inundated by the SEM’s electron beam, electrons are thrown from the atoms on the sample’s exterior. The subsequent electron openings in these atoms are then stocked by electrons from a higher state, and an X-ray is released to stabilize the energy

82

3.  Phytosynthesis of Nanoscale Materials

­ ifference between the two states. It can be used to basically determine the number of NPs d produced with a thin film of biomass (Menon et al., 2017). It is shown that the recent availability of aberration corrected microscopes and multivariate statistical analysis (MSA) techniques has allowed us to overcome many of the intrinsic limitations previously encountered when attempting SEM-EDS spectrum imaging on nanoscopic volumes of material. EDS is a cheap, versatile way to acquire a quick compositional analysis. However, samples must be sustainable in a vacuum and a careful review of the data is essential due to the technique’s propensity to produce data overlaps (Herzing et al., 2008; Slater et al., 2016). 7.1.9  Zeta Potential (ZP) ZP is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle, which provides information about the surface charge of particles (Noruzi, 2015). ZP has emerged as a simple tabletop technique executable under ordinary lab environments to investigate the (hydrodynamic) size and surface charge of NPs. Surface charge and particle size are the two most commonly mentioned factors responsible for a range of biological effects of NPs including cellular uptake, toxicity, and dissolution (Bhattacharjee, 2016). ZP measurements have gained popularity as simple, easy, and reproducible tools to ascertain particle size and surface charge. Nanoparticles with a ZP between –10 and +10 mV are considered approximately neutral, while NPs with ZP of greater than +30 mV or less than –30 mV are considered strongly cationic and strongly anionic, respectively (Bhattacharjee, 2016). Since most cellular membranes are negatively charged, ZP can affect a nanoparticle’s tendency to permeate membranes, with cationic particles generally displaying more toxicity associated with cell wall disruption (Rajeshkumar and Bharath, 2017). The Malvern Zetasizer series of instruments are widely popular with university graduates and have emerged as a gradual evolution of the original Malvern Correlator marketed in 1970. Overall these instruments have three major components: laser, sample, and light detector (Bhattacharjee, 2016). 7.1.10  Fourier Transforms Infrared Spectroscopy (FTIR) FTIR is a molecular vibrational spectroscopy that dissects chemical functional groups in different absorbance regions between 4000 and 400 cm−1 (Mohammadlou et al., 2016). FTIR is a noninvasive, suitable, valuable, cost effective, and simple technique to investigate the role of biomolecules in the reduction of metal ion to metal NPs (Rajeshkumar and Bharath, 2017).

7.2  Quantitative Analysis 7.2.1 Transmission Electron Microscope (TEM) The sample preparation for TEM characterization involves placing a drop of solution on a carbon-coated copper grip that was dried at a room temperature, while the residual solution was removed with blotting paper (Menon et al., 2017). TEM is a useful real-space analysis method and helps to observe the particle size and morphology of a material in nanoscale and to study the crystal structure meticulously with highest resolution. On the other hand, an alternate method, such as TEM, is suitable to confirm that the particle sizes are not due to agglomerates (Mohammadlou et al., 2016).



7  Metal Nanoparticles Characterization

83

7.2.2  Dynamic Light Scattering (DLS) DLS technique, also called photon correlation spectroscopy, measures the hydrodynamic average particle size of NPs and their distributions using the dynamic light scattering method. DLS is faster and less expensive than electron microscopy techniques in size analysis and has been used in some studies (Noruzi, 2015). This method is defined as a technique that changes the scattering light intensity fluctuation to obtain the sample average hydrodynamic diameter. DLS being a sensitive method for detection of protein-bound nanoparticles can detect smaller amounts of large particles formed due to agglomeration or contamination causing ambiguities in particle sizes. Real-time monitoring NPs size can be realized by DLS because the measurement process of DLS is rapid and sensitive to solution phase detection. Currently, this technique has been applied to detect metal ions and cancer biomarkers (Mohammadlou et al., 2016). 7.2.3  High Angle Annular Dark Field (HAADF) Several electron microscopy techniques, such as HAADF, are used to study the mechanism by which metal NPs interact with bacteria. HAADF is a powerful technique for analysis of biological samples, such as proteins, and bacteria interfaced with inorganic NPs. HAADF images are mainly formed by electrons that have undergone Rutherford backscattering. As a result, image contrast is related to differences in atomic number with intensity varying as ~Z2 (Mohammadlou et al., 2016). 7.2.4  Coupled Plasma Mass Spectrometry (ICP-MS) ICP/AES technique is used to determine the reaction yield and the conversion value of metal ions to metallic NPs. A few studies have measured the recovery of the synthesis reaction (Noruzi, 2015). ICP-MS has become the technique of choice for detection and characterization of nanoparticles in solution. Compared with other techniques, ICP-MS is unique in its ability to provide information on nanoparticle size, size distribution, elemental composition, and number concentration in a single, rapid analysis. In addition, only ICP-MS can simultaneously determine the concentration of dissolved analyte in the sample (Allabashi et al., 2008). A few studies have measured the recovery of the synthesis reaction (Noruzi, 2015). For example, Ag concentrations in the deionized and the original AgNPs solutions can be determined by ICP spectrometry (Mohammadlou et al., 2016). In a study carried out by Dubey et al., a reaction yield of larger than 90% was obtained for the formation of platinum NPs at 95°C using Diopyros kaki leaf extract and for the formation of AgNPs using Magnolia kobus and D. kaki leaf extracts (Noruzi, 2015). A direct and simple inductively ICP-MS method for the determination of AuNP with different particle sizes ranging from 5 to 20 nm and suspended in aqueous solutions is described by Allabashi et al. (2008). 7.2.5  X-ray Photoelectron Spectroscopy (XPS) X-ray photoelectron spectroscopy (XPS) is a surface chemical analysis technique that can be used in elemental analysis of the sample and determination of element speciation. In this technique, the sample is irradiated with X-ray beams while the kinetic energy and number of electrons that escape from the surface of the material are simultaneously measured. Since each element produces a characteristic set of XPS peaks at characteristic binding energy values, this technique can directly identify each element that exists on the surface of the material

84

3.  Phytosynthesis of Nanoscale Materials

being analyzed (Noruzi, 2015). For example, AgNPs can be investigated by XPS to characterize the nature of the surfactant chemisorbed to the surface. XPS is used to examine the valence of the resulting AgNPs while it also provides further information regarding the structure of AgNPs encapsulated in the organic network (Mohammadlou et al., 2016). XPS can also be used for the identification of metallic NPs that do not have strong plasmon resonance absorption, such as palladium and platinum.

8  VARIOUS FACTORS AFFECTING THE MORPHOLOGY, SIZE, AND YIELD OF METAL NPS Metal NPs preparation using plants (inactivated plant tissue, plant extracts, and living plants) is an important branch of biosynthesis processes. It has long been known that plants have potential to reduce metal ions both on their surface and in various organs and tissues remote from the ion penetration site (Makarov et  al., 2014). Biomolecules existing in plant extracts, including enzymes, proteins, amino acids, vitamins, polysaccharides, and organic acids, such as citrates, are potentially able to reduce metal ions (Mohammadlou et al., 2016). The extract of various parts of plants such as leaves, seeds, fruit, flowers, roots, peel, gum, stem, and barks have been applied for synthesis of metal NPs (Rai et al., 2008). Mechanisms of interaction between NPs and plants could be chemical or physical. Chemical interactions involve the production of reactive oxygen species, disturbance of ion cell membrane transport activity, oxidative damage, and lipid peroxidation. Following entry into the plant cells, NPs after mixing behave as metal ions and react with sulfhydryl and carboxyl groups and ultimately alter the protein activity. The formation of small, large, and undefined-shape NPs is dependent on the presence of phytochemicals like phenolic amides, piperine, polysaccharides, and other reducing sugars that might have played an important role in the synthesis of metal NPs (Rajeshkumar, 2016).

8.1  Plant Metabolites Affecting the Formation of Metal NPs Several secondary metabolites and enzymes have relatively promoted the formation of metallic NPs from the corresponding ionic compounds (Makarov et  al., 2014). The reduction reaction mainly involved plant biomolecules (secondary metabolites), such as sugars (polysaccharides), proteins, organic compounds, pigments, and plant resins. Various plant metabolites, including terpenoids, polyphenols, sugars, alkaloids, phenolic acids, and proteins, play an important role in the bioreduction of metal ions to form NPs (Makarov et al., 2014; Mohammadlou et al., 2016). The main types of plant metabolites involved in the synthesis of metal NPs included terpenoids (eugenol), flavonoids (Abdelghany et al., 2017) (luteolin, quertcetin), a reducing hexose with the open chain form, amino acids (tryptophan and tyrosine). These secondary metabolites are known as key sources for controlling the various acute diseases (Dubey et  al., 2010). The proposed reduction reaction proved that the secondary metabolites are the main factors for the biosynthesis of metallic NPs. The plant extracts contain numerous functional groups such as CC (Alkenyl), CN (amide), OH (phenolic and alcohol), NH (amine), CH and COO (carboxylic group), CO and OH stretching of carboxylic acids or their esters, CO (nitro group), CH and CO of alkanes



8 Various Factors Affecting the Morphology, Size, and Yield of Metal NPs

85

(Elumalai and Velmurugan, 2015; Ali et al., 2016; Anbuvannan et al., 2015; Sundrarajan et al., 2015). Moringa oleifera, Magnolia kobus, and Diopyros kaki leaf extracts promote the reaction in the presence of biological compounds containing functional groups such as OH; NH2; H3CO; HOCO, CC, and CH aromatic stretching; NCS stretching thiamine; CH; CC; and NH (Song et al., 2009a; Prasad and Elumalai, 2011; Matinise et al., 2017). Phenolic acids are a large family of secondary metabolites having hydroxyl benzoic or hydroxyl cinnamic structures. It has been reported that they possess hydroxyl and carbonyl groups that are able to bind to metals. For example, the presence of phenolic compounds and proteins in the seed extract of Macrotyloma uniflorum may be the key factors for the formation of AgNPs (Vidhu et al., 2011). Therefore, the root extract of R. hymenosepalus is rich in polyphenols such as catechins and stilbenes molecules, which act as reducing and stabilizing agents for AgNPs production. The main mechanism is hydrogen abstraction due to the OH groups in the polyphenol molecules (Rodríguez-León et  al., 2013). The plants derived secondary metabolites, such as phenolics (Abdelghany et al., 2017; Moulton et al., 2010), proteins (Ali et al., 2016), aromatic and aliphatic amine (Nagajyothi et al., 2014; Narayanan and Sakthivel, 2010), polysaccharides (such as chitosan) (Huang and Yang, 2004; Wei and Qian, 2008), flavonoids (Abdelghany et al., 2017; Arokiyaraj et al., 2014; Raghunandan et al., 2010), terpenoids (Soundarrajan et al., 2012; Nabikhan et al., 2010), tannins (Kuppusamy et al., 2016; Islam et al., 2015b), carboxylic acid (Elumalai and Velmurugan, 2015), ascorbic acid (Bindhu et al., 2014; Rai et al., 2006; Soundarrajan et al., 2012), citric acid and malic acid (Bindhu et al., 2014) were synthesized NPs in an ecofriendly method. There are many reports about the bioreduction of metal ions to NPs by secondary metabolites. The aqueous leaf extracts of Mirabilis jalapa were demonstrated to have maximum secondary metabolites, such as tannins, flavonoids, alkaloids, and phenols. Steroids, saponins, and glycosides are absent in aqueous extract of Mirabilis jalapa. Saponins and alkaloids show their presence in silver nanoparticle synthesized leaf extract. Flavonoid, tannins, phenol, glycosides, and steroids were not found in the silver nanoparticle synthesized leaf extract (Asha et al., 2017). Bioreduction involves reducing Zinc oxide ions to 0 valence ZnO NPs with the help of phytochemicals like polysaccharides, phosphorous compounds, polyphenolic compounds, vitamins, diketone, vinyl, amino acids, secondary sulfornamide, alkaloids, terpenoids secreted from the plant (Agarwal et al., 2017). The chemical components of Scutellaria barbata, mainly including diterpenoids, flavonoids, alkaloids, polysaccharides, and steroids were involved in bioreduction of AuNPs (Wang et al., 2009). At the Stevia rebaudiana leaf extract, proton nuclear magnetic resonance spectrum of the AgNPs reveals the existence of aliphatic, alcoholic, and olefinic CH2 and CH3 groups, and some aromatic compounds but no sign of aldehydes or carboxylic acids; Ketones play an active role for the formation of AgNPs in plant extracts, of course. (Yilmaz et  al., 2011). The FTIR result of fruit peel extract of Punica granutum clearly showed that the extracts containing phenolic hydroxyls (OH band) and aromatic ring present in the extract as a functional group act in capping the AuNPs synthesis (Ganeshkumar et  al., 2013). On the other hand, AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups in the leaf extract of Hibiscus rosa sinensis from synthesis gold and AgNPs (Philip, 2010). Ankamwar et al. (2005a) investigated the effect of different organic solvent vapors like methanol, benzene, and acetone on the conductivity of tamarind leaf extract reduced gold nanotriangles (Ankamwar et al., 2005a). AuNPs were functionalized with leaf extract of Stevia rebaudiana biomolecules

86

3.  Phytosynthesis of Nanoscale Materials

that have ­primary amine group (NH2), carbonyl group and other stabilizing functional groups (Sadeghi et  al., 2015a). The FTIR spectrum of C. amboinicus leaf extract confirmed the involvement of aromatic amines, amide (II) groups, and secondary alcohols in capping and reduction of AuNPs (Narayanan and Sakthivel, 2010). The spectra of the S. campanulata aqueous leaf extract gave an O-H stretch of polyphenols, nitrile group from proteins and double substituted aromatic bending (Ochieng et al., 2015). From the FTIR result, the soluble elements present in Sargassum muticum (brown seaweed) water extract, such as C-C groups from aromatic rings, carbonyl (–C=O) group, and the C–O from C–O–SO3 group, could have acted as capping agents preventing the aggregation of NPs in solution, thus playing a relevant role in their extracellular synthesis and shaping (Mahdavi et al., 2013). The FT-IR spectra of Calotropis procera aqueous leaf extract indicate the presence of hydroxyl groups, aldehydes, amines, ketones, and carboxylic acids, which are responsible for biochemical reaction (Gawade et  al., 2017). The rambutan peel waste has significant potential due to its polyphenols and has an easy electron loosing capacity, which results in the formation of zinc-ellagate complex formation (Yuvakkumar et al., 2014). Aromatic hydroxyl groups present in Nephelium lappaceum peel extracts ligate with zinc ions to form the zinc-ellagate complex at pH 5–7 and synthesis ZnO NPs (Yuvakkumar et al., 2014). The TEM analysis revealed that Galaxaura elongata mediated nanoparticle synthesis produced various shapes. The FTIR results confirmed the presence of carbonyl stretch and N–H stretch having a stronger potential to bind with the metal nanoparticle, helping in the formation of a coat that prevents the particle from agglomeration. The algal extract andrographolide, alloaromadendrene oxide, glutamic acid, hexadecanoic acid, oleic acid, eicosenoic acid, stearic acid, gallic acid, epigallocatechin catechin, and epicatechin gallate may help in reducing, then stabilizing and capping as a covering agent (Abdel-Raouf et al., 2017). As mentioned above, various plant metabolites, including terpenoids, polyphenols, sugars, alkaloids, phenolic acids, and proteins play an important role in the bioreduction of metal ions, yielding NPs (Makarov et al., 2014). Specific components, such as emodin, a purgative resin with quinone compounds that is present in xerophytic plants, are responsible for metal nanoparticle synthesis; cyperoquinone, dietchequinone, and remirin in mesophytic plants are useful for metal nanoparticle synthesis (Singh et al., 2016a). 8.1.1 Terpenoids and Flavonoids Using FTIR spectroscopy of NPs synthesized in plants/plant extracts, it has been demonstrated that terpenoids are often associated with NPs. Terpenoids are a group of diverse organic polymers synthesized in plants from five-carbon isoprene units which display strong antioxidant activity (Makarov et al., 2014; Mohammadlou et al., 2016). Shankar et al. initially suggested that terpenoids play a key role in the transformation of silver ions into NPs in reactions using extracts from geranium leaves (Makarov et  al., 2014). The main terpenoid of Cinnamomum zeylanisum extracts indicated eugenol, which was responsible for reduction of HAuCl4 and AgNO3 to NPs (Singh et  al., 2010b). Based on the FTIR spectroscopy data, Shankar et al. was suggested that dissociation of a proton of the eugenol OH-group results in the formation of resonance structures capable of further oxidation. This process is accompanied by the active reduction of metal ions, followed by nanoparticle formation (Shankar et al., 2003a). AuNPs synthesized using Magnolia kobus leaf extract are surrounded by some proteins and terpenoids having functional groups of amines, alcohols, ketones, aldehydes,



8 Various Factors Affecting the Morphology, Size, and Yield of Metal NPs

87

and carboxylic acids (Song et  al., 2009a). Respectively, the phenolic and polyphenol substances present in the plant leaf extracts of C. pepo and M. crispa, played a major role in the AuNPs synthesis (Chandran et al., 2014) and other similar products using aqueous extract of Terminalia chebula fruit, the polyphenols present in the extract in the form of tannins hydrolyze to give gallic acid, ellagic acid, glucose, etc. Transformation of phenolics to the quinone form enables the reduction of metal ions (FeO and Pd) to metal NPs. Oxidized polyphenols act as stabilizing agents (Mohan Kumar et al., 2013b). On the other hand, polyphenols responsible for reduction of Au3+ to Au0 were identified in T. chebula fruit extract. The oxidized forms of polyphenols formed coordination with the surface of AuNPs, which inhibited their further growth and aggregation (Li et al., 2007). The FTIR spectra results from early reports indicated that the plant extract phytocompounds, such as phytosterol, flavonoids, alkaloids, triterpenoids, amino acids, and proteins, might be participating in the process of nanoparticle synthesis (Vijayakumar et  al., 2011; Jayaseelan et al., 2013). Flavonoids are a large group of polyphenolic compounds that comprise several classes including anthocyanins, isoflavonoids, flavonols, chalcones, flavones, and flavanones, which can actively chelate and reduce metal ions into NPs (Mohammadlou et al., 2016). Flavonoid compounds possess hydroxyl and ketonic groups, which are able to bind to metals (Das and Velusamy, 2014). Flavonoids contain various functional groups capable of nanoparticle formation. It has been postulated that the tautomeric transformations of flavonoids from the enol-form to the keto-form may release a reactive hydrogen atom that can reduce metal ions to form NPs (Makarov et  al., 2014). For example, it is believed that in the case of Ocimum basilicum extracts it is the transformation of flavonoids luteolin and rosmarinic acid from the enol- to the keto-form that plays a key role in the formation of AgNPs from Ag ions (Ahmad et al., 2010; Makarov et al., 2014). The flavonoid C-glycosides and O-glycoside derivatives act as reducing and capping agents for the synthesis of AgNPs using Passiflora tripartite fruit extract (Kumar et al., 2015b). The hydroxyl groups present in flavonoids and polyphenols in the leaf extract of Sesbania gandiflora are converted to carbonyl groups, reduced the HAuCl2 ions, and capped the NPs (Das and Velusamy, 2014). S. alba contains flavonoids like quercetin and tannis; however, the major phenolic content present is salicin. The presence of hydroxyl group and glucosidal linkages in the salicin may be responsible for the formation of AuNPs (Islam et al., 2015b). Stoechospermum marginatum, a brown alga, produced AuNPs measured from TEM and the FTIR analysis showed that the reduction is possible due to the terpenoids containing the hydroxyl group present in the seaweed (AbdelRaouf et al., 2017; Arockiya Aarthi Rajathi et al., 2012). Moreover, the internal mechanism of the conversion of ketones to carboxylic acids in flavonoids is likely to be involved in Au3+ ion reduction. Interestingly, some flavonoids are able to chelate metal ions with their carbonyl groups or π-electrons. These groups chelate various metal ions such as Fe2+, Fe3+, Cu2+, Zn2+, Al3+, Cr3+, Pb2+, and Co2+. The presence of such mechanisms may indeed explain the ability of flavonoids to be adsorbed onto the surface of a nascent nanoparticle. This probably means that they are involved in the stages of initiation of nanoparticle formation (nucleation) and further aggregation, in addition to the bioreduction stage. Moreover, isolated flavonoids and flavonoid glycosides have the ability to induce the formation of metal NPs. For example, apiin (flavon glycoside) was extracted from Lawsonia inermis and used for the synthesis of anisotropic Au and quasi-spherical AgNPs with an average size of 21–30 nm (Kasthuri et al., 2009b; Makarov et  al., 2014). Flavanones could be adsorbed on the surface of metal NPs,

88

3.  Phytosynthesis of Nanoscale Materials

possibly by interaction through carbonyl groups or π-electrons in the absence of other strong ligating agents in sufficient concentration (Islam et al., 2015b). 8.1.2 Sugars In plant extracts, sugar can also be used for the synthesis of metal NPs. It is known that monosaccharides, such as glucose (linear and containing an aldehyde group) or galactose sulfate polysaccharides, can act as reducing agents (Abdel-Raouf et al., 2018; Makarov et al., 2014). Monosaccharides containing a keto-group (e.g., fructose) can act as antioxidants only when they have undergone a series of tautomeric transformations from a ketone to an aldehyde. Moreover, the reducing ability of disaccharides and polysaccharides depends on the ability of any of their individual monosaccharide components to adopt an open chain form within an oligomer and, hence, to provide access (of a metal ion) to an aldehyde group. For example, the disaccharides maltose and lactose have reducing ability, since at least one of their monomers can assume an open chain form. Sucrose, in contrast, has no ability to reduce metal ions, because glucose and fructose monomers are linked in such a way that the open chain form is not available. It was found that glucose is capable of participating in the synthesis of metal NPs of various morphologies, whereas fructose mediates the synthesis of monodispersed NPs of gold and silver. Glucose was also noted to be a stronger reducing agent than fructose, because the antioxidant potential of fructose is limited by the kinetics of tautomeric shifts (as discussed above). It was shown that sucrose is unable to reduce silver nitrate or palladium chloride into NPs (Makarov et al., 2014; Andreescu et al., 2007). However, when these metal salts were replaced by tetrachloroauric and tetrachloroplatinic acids, NPs were formed in the presence of sucrose, which is likely due to the acidic hydrolysis of sucrose into free glucose and fructose, which have an open chain-form structure. It is currently believed that the sugar aldehyde group is oxidized into a carboxyl group via the nucleophilic addition of OH-, which in turn leads to the reduction of metal ions and to the synthesis of NPs. A similar mechanism was proposed for the bioreduction of gold ions using the magnolia vine extract (Shankar et al., 2003a; Makarov et al., 2014). 8.1.3  Peptides and Proteins FTIR analysis of NPs synthesized in plants or plant extracts revealed that nascent NPs are very frequently found in association with proteins (Zayed et  al., 2012; Makarov et  al., 2014). Proteins including different amino acids are capable of reducing several metal ions, resulting in their NPs (Mohammadlou et al., 2016). The approaches that have recently been used for the “green” synthesis of metal NPs combine the use of plant extracts with the exogenous supplementation of the in vitro reactions with biomatrices: peptides, and proteins, whose amino acid sequence and structure are optimized for the efficient production of NPs. Tryptophan and amino acids, such as tyrosine, arginine, and lysine, possess superior ability to reduce metal ions. Amino acids were found to differ in their ability to bind metal ions and reduce them (Makarov et al., 2014). The carbonyl group of amino acids, such as lysine, cysteine, arginine, and methionine residues, and proteins has potential to bind metal ions to form NPs (Mohammadlou et al., 2016; Tran et al., 2013). However, a polypeptide composed only of tryptophan residues is much less effective at forming NPs than a mixture of tryptophan molecules interspersed with other amino acids, likely due to strong binding of the reduced ion, which in turn is inhibitory to further reduction. In turn, peptides that consist of different



8 Various Factors Affecting the Morphology, Size, and Yield of Metal NPs

89

amino acids capable of strongly binding metal ions are also poorly suited as a biomatrix for the synthesis of NPs due to entropic effects. Peptides comprising amino acids that weakly bind tetrachloroauric acid ions, such as glutamic or aspartic acids, are also inefficient in the synthesis of NPs because of rapid dissociation of the peptide – metal ion complex. Therefore, the most suitable peptides for the formation of metal NPs are those in which reducing and strongly binding amino acid residues (e.g., tryptophan) alternate with weakly binding amino acids which act as an up-regulator (Haverkamp and Marshall, 2009; Makarov et al., 2014). Other studies have shown that aspartate can reduce HAuCl4 to form AuNPs, although valine and lysine do not possess this ability (Mandal et al., 2002). Tan et al. (2010) recently analyzed all of the 20 natural α-amino acids to determine their potential for reduction or binding of metal ions. They established that tryptophan is the strongest reducing agent for Au ions, whereas histidine is one of the strongest binding agents for Au ions (Tan et al., 2010; Makarov et al., 2014). Amino acids can bind to metal ions through the amino and carbonyl groups of the main chain or through side chains (Abdel-Raouf et al., 2018), such as the carboxyl groups of aspartic and glutamic acid or a nitrogen atom of the imidazole ring of histidine. Other side chains binding metal ions include the thiol (cysteine), thioether (methionine), hydroxyl (serine, threonine, and tyrosine), and carbonyl groups (asparagine and glutamine) (Makarov et al., 2014). The peptides may play a major role in the reduction of Ag+ to AgNPs (Kannan et al., 2013). Bar et al. indicated that the smaller particles are mostly stabilized by the cyclic octapeptide (i.e., curcacycline A) and cyclic nonapeptide (i.e., curcacycline B). On the other hand, the larger and uneven shape particles are mainly stabilized by the curcain, an enzyme present in the latex (Bar et al., 2009a). Leaf extract of S. alba indicated with FTIR show the possible involvement of amines, amides, and aromatic groups in the reduction gold ion and may act as capping agents (Islam et al., 2015b). The spectrum of the biomass sugar beet pulp of Beta vulgaris after gold reduction shows the amide I band. This suggests that proteins are responsible for Au (III) reduction and AuNPs stabilization. In addition, polysaccharides in the sugar beet pulp would be involved in the reduction process and their hydroxyl groups oxidized to carbonyl group. Sugar beet pulp may contain proteins that can act as capping and stabilizing agents of AuNPs. The surface-bond is established through free amine groups or cysteine residues in the proteins (Castro et al., 2011). After amino acids are linked to the peptide chain, their individual ability to bind and reduce metal ions may change. For example, the formation of the peptide backbone changes the functionality of the r-carbon of carboxylic acids and amines of some amino acid residues since they move to a form inaccessible for interaction with metal ions. However, free side chains of amino acids can still participate in the binding and reduction of metal ions. The suitability of side chains for this interaction may change depending on the amino acid sequence, which could affect the accessibility of individual groups. The work by Tan et al. (2010) explained in detail how the amino acid sequence may affect the protein’s ability to chelate and/or reduce metal ions. It was found that synthesized peptides, composed of amino acids capable of effective binding of metal ions, and of amino acids possessing high reducing activity, had lower reduction parameters than expected. It was suggested that the strong sequestration of metal ions to the peptide was inhibitory to their subsequent reduction by reducing amino acids. It was also found that peptides containing amino acids that weakly bind metal ions such as leucine, phenylalanine, and proline were ineffective in reducing tetrachloroauric acid anions, probably because of their inability to retain metal ions close to the reduction sites.

90

3.  Phytosynthesis of Nanoscale Materials

It was ­assumed that protein molecules facilitating the formation of NPs from metal ions display high reducing activity and high potential for attracting metal ions to the regions of a molecule that are responsible for reduction, but that their chelating activity is not excessive (Makarov et al., 2014; Tan et al., 2010).

8.2  Culturing Factors Affecting the Formation of Metal Nanoparticles in Plants The reduction process of metal ions with the formation of NPs is affected by a large number of factors; several factors including pH, incubation temperature, reaction time, concentration, and electrochemical potential of a metal ion can have effect on the metal ions reduction process (Makarov et al., 2014; Mohammadlou et al., 2016). For example, the rate of AuNPs fabrication and their stability is an important aspect in industrial production. Thus, the influence of reaction conditions should be properly monitored. Morphology of AuNPs depends on the pH, temperature, incubation time, and concentrations of the plant extract and that of the metal salt (Siddiqi and Husen, 2017). The results of synthesis of AgNPs using Solanum xanthocarpum berry extract showed that the time of reaction, temperature and volume ratio of S. xanthocarpum extract to AgNO3 could accelerate the reduction rate of Ag+ and affect the AgNPs size and shape (Amin et al., 2012). In the following section we have summarized some of the recent reports covering this aspect. 8.2.1 pH pH is one of the important factors for NPs synthesis (Chandran et al., 2014). The pH value of the plant extracts has a great influence on the formation of NPs. In fact, the charge of natural phytochemicals of the plant extracts changes by variation in pH, and affects their ability to bind and reduce metal ions during nanoparticle synthesis. This may affect the shape, size, and yield of formed NPs (Makarov et  al., 2014; Mohammadlou et  al., 2016). In particular, larger particles tend to be produced at lower acidic pH values compared to high pH values (Shah et al., 2015). Gardea-Torresdey et al. found that pH is an important factor in the biosynthesis of colloidal gold using alfalfa biomass and concluded that the size of NPs varied with the change in pH. Mock et al. also reached similar conclusions and reported that pH is responsible for the formation of NPs of various shapes and size. For example, the size of gold nanoparticles produced by Avena sativa was highly dependent on the pH value. Jeyaraj et al. (2013) demonstrated variation in the pH before and after the synthesis of AgNPs using leaf extract of Podophyllum hexandrum; after synthesis the pH of the colloid is lower in most cases. In alkaline pH, the aggregation of AgNPs was believed to be favored over the nucleation to form new and large NPs. Jeyaraj et al. reported the vital role of pH in controlling the shape and size of Ag NPs (Jeyaraj et al., 2013). Rod-shaped AuNPs synthesized using oat biomass were larger (25 to 85 nm) when formed at pH 2 and relatively smaller (5–20 nm) at pH 3 and 4. The study suggested that between pH 3 and 4 more accessible functional groups contained within the extract were available for particle nucleation. They speculated that at low pH (pH 2), the AuNPs prefer to aggregate to form larger NPs rather than to nucleate and form new NPs. In contrast, at pH 3 and 4, more functional groups (carbonyl and hydroxyl) are available for gold binding; thus a higher number of new Au (III) complexes would bind to the biomass at the same time which will nucleate separately and form NPs of relatively small size (Akhtar et al., 2013). Similar



8 Various Factors Affecting the Morphology, Size, and Yield of Metal NPs

91

findings were obtained by Satishkumar et al., who tested the effect of pH during synthesis of AgNPs using Cinnamom zeylanicum powder and bark extract over a wider pH range (1–11) and concluded that pH of the solution dropped in most of the cases after the synthesis of AgNPs. The formation of large ellipsoidal AgNPs was observed at lower or acidic pH, while at higher or alkaline pH highly dispersed, small and spherical NPs tended to form. They also speculated that at higher pH, availability of a large number of functional groups facilitates a higher number of Ag(I) to bind and subsequently form a large number of NPs with smaller diameter (Akhtar et al., 2013). On the other hand, when C. zeylanicum bark extract was used to synthesize PdNPs there was a slight increase in particle size with increasing pH. When the pH was less than 5, the particle ranged from 15 to 20 nm and when the pH was greater than 5, particles ranged in size from 20 to 25 nm (Sathishkumar et  al., 2009a). At pH 2 the most accessible metal ions are apparently involved in a smaller number of nucleation events, which leads to agglomeration of the metal (Sathishkumar et al., 2010; Makarov et al., 2014). In contrast, it was demonstrated using fruit extracts from pears that hexagonal and triangular gold nanoplates are formed at alkaline pH values, whereas NPs do not form at acidic pHs (Ghodake et al., 2010). Variation of pH (from 6.8 to 8.5) of the reaction medium consisting of silver nitrate and hibiscus leaf extract gave AgNPs of different shapes and spherical shapes formed at pH 7.5 (Philip, 2010). An increase in pH affected a decrease in the size of the AgNPs synthesized by extract of red algae Gracilaria birdiae (de Aragão et al., 2016). A substantially larger number of AgNPs are synthesized at alkaline pHs in the case of silver ions (1+) and the tuber powder of Curcuma longa (turmeric), the extracts of which may contain more negatively charged functional groups which are capable of efficiently binding and reducing silver ions and, thus, more NPs were synthesized (Sathishkumar et al., 2010). With the formation of gold nanowires using sugar beet pulp at pH 9, the NPs are spherical and small, approximately 10 nm in diameter. With increasing alkalinity at pH 10, the particle size increased up to 25 nm because of the aggregation of gold nuclei to form nanorods. Finally, very thin nanowires were obtained at pH 11 (15 nm of diameter) (Castro et  al., 2011). Islam et  al. (2015a) have demonstrated that the AuNPs were found most stable in an acidic pH range of 4–5 and basic pH range of 10–11 (Islam et al., 2015a). The average size of the gold particles synthesis with mango peel extract was 6.0–2.77 nm at pH 9.0 and average size 18.0–3.67 nm at pH 2.0 (Yang et al., 2014). Another example of size- and shape-controlled biological synthesis was shown by Kora et al. (2012), who demonstrated the size-controlled green synthesis of AgNPs of 5.7– 0.2 nm by Anogeissus latifolia. The AuNPs synthesis by Salix alba leaf extract was quite stable in an acidic medium. With the brown alga Fucus vesiculosus, pH 7 produced uniform and spherical NPs smaller than those obtained at pH 4, which showed a greater variety of sizes and shapes. In many gold biosorption studies, efforts have been made to raise the optimum pH range from acid values (Mata et al., 2009). Andreescu et al. (2007) reported the rapid and complete reduction of silver at elevated pH and observed a negative zeta potential of the synthesized AgNPs at different pH. They reported that increase in pH results in increase of the absolute value of the negative zeta potential, which led to the formation of highly dispersed NPs. This phenomenon could be related to the electrostatic repulsion at high pH or attributed to the high absolute value of the negative zeta potential (Andreescu et al., 2007). In contrast, Dwivedi and Gopal revealed that silver and AuNPs are stable in a wider range of pH as they observed very small variation in the zeta potential values between pH 2–10 in their study using Chenopodium album (Carrillo-López et al., 2014). Recently, Veerasamy et al. (2011), while

92

3.  Phytosynthesis of Nanoscale Materials

working on ­mangosteen leaf extract, reported that at low pH, aggregation of AgNPs is favored over nucleation. However, higher pH facilitates nucleation and subsequent formation of large number of NPs with smaller diameter (Veerasamy et al., 2011; Akhtar et al., 2013). 8.2.2  Reaction Temperature Temperature is one of the important factors affecting the formation of NPs in plant extracts and influences the stability, activity, and chemical characteristics of materials (Islam et  al., 2015b). Temperature increase improves the reaction rate and efficiency of nanoparticle synthesis. It seems that an increase in temperature elevates the nucleation rate (Mohammadlou et al., 2016). It is a well-known fact that when the temperature is increased, the reactants are consumed rapidly, eventually leading to the formation of smaller NPs (Bankar et al., 2010b). It was found that in alfalfa plants (M. sativa) triangular AgNPs formed only at temperatures above 30°C (Lukman et al., 2011). Furthermore, experiments on the synthesis of AgNPs in Aloysia citrodora leaf extract demonstrated that increasing the reaction temperature is accompanied by an increase in the efficiency of the silver ion reduction (Luis López-Miranda et al., 2016). Moreover, crystal particles are formed much more frequently at high temperatures than at room temperature. It is assumed that elevating the temperature increases the nucleation rate. In experiments with Cassia fistula extracts, it was found that temperature may also affect the structural form of the synthesized NPs; silver nanoribbons are mainly formed at room temperature, whereas spherical NPs predominate at temperatures above 60°C (Lin et al., 2010). In this case it is believed that higher temperatures alter the interaction of phytochemicals with the nanoparticle surface, thereby inhibiting incorporation of adjacent NPs into the structure of nanoribbons. Furthermore, in some situations higher temperatures may facilitate the nucleation process to the detriment of the secondary reduction process and further condensation of a metal on the surface of nascent NPs. This phenomenon is believed to explain the formation of the spherical AuNPs in Nyctanthes arbortristis alcoholic extracts at 80°C in contrast to the NPs of different morphology and “nanocolors” formed at room temperature (Das et al., 2011; Makarov et al., 2014). Synthesis of AgNPs at a reaction temperature of 25°C via Citrus sinensis peel extract produced particles with an average size of around 35 nm. However, when the reaction temperature was increased to 60ºC, the average particle size decreased to 10 nm (Shah et al., 2015). SEM and TEM images of AgNPs (Magnolia kobus and Diopyros kaki leaf extract) showed that a mixture of plate (triangles, pentagons, and hexagons) and spherical structures (size, 5–300 nm) were formed at lower temperatures, while smaller spherical shapes were obtained at higher temperatures and leaf broth concentrations (Song et al., 2009a). It is evidential that the yield of AgNPs has a positive correlation with the increase in temperature. Andreescu et al. also reported a rapid synthesis rate of AgNPs at higher temperatures. Additionally, Sathiskumar et  al. realized the increase in the surface plasmon resonance with the increase in temperature, confirming the positive correlation between the yield of the NPs and the temperature (Andreescu et  al., 2007; Akhtar et  al., 2013). Dubey et  al. also observed during their study using Tanacetum vulgare fruit extract that with the increase in temperature from 25°C to 150°C, an increase in the sharpness of absorption peaks was found for both Ag and AuNPs. This is so because with the increase in temperature the rate of reaction is also increased which thus enhances the synthesis of NPs (Dubey et al., 2010; Akhtar et al., 2013). Jeyaran et al. believed that reduced synthesis of NPs using leaf extract of Podophyllum hexandrum was obtained at



8 Various Factors Affecting the Morphology, Size, and Yield of Metal NPs

93

low temperature because at lower temperature the Plasmon band was not accompanied with increased intensity. Increase in temperature is reflected in the intensity of SPR peak due to increasing rate of NPs synthesis showed the sharpness of the absorbance peak depends on the size of the NPs (Jeyaraj et al., 2013). Reaction rate and particle formation rate appears to become faster when reaction temperature increases, however, the average particle size decreases and particle conversion rate steadily increases with increasing temperature (Shah et al., 2015). 8.2.3  Concentration and the Reducing Agents A variation in the biological material and metal salt concentration is known to influence nanoparticle synthesis (Bankar et al., 2010b). The size of the NPs depends on the concentration of metal salt; for example, Ag(NH3)2 is a stable complex ion resulting from ammonia’s strong affinity for Ag+; therefore the ammonia concentration and nature of the reductant must play a major role in controlling the AgNPs (Prasad, 2014). Jeyaraj et al. (2013) demonstrated that higher metal ion concentration played a vital role in synthesis of AgNPs, while the particle synthesis rate was negligible at lower concentration but variation in initial concentration of Podophyllum hexandrum leaf extract did not affect the shape and size of the NPs formed. (Jeyaraj et al., 2013). When the precursor chloroauric acid was subjected to increasing concentrations of extract, the resulting nanoparticle shape changed from triangular to spherical. Similarly, by varying the amount of Aloe vera leaf extract in the reaction medium containing chloroaurate ions, Chandran et al. (2006) were able to influence the ratio of gold triangular plates to spherical NPs. S. alba-mediated AuNPs were relatively stable when the volume of salt increased. AgNPs synthesis by Sacha inchi showed that activity and rate of the reaction increase with increasing the concentration of NPs (Kumar et al., 2014). Silver or gold precursors biosynthesized by Rosa rugosa leaf extract within 10 min. The synthesized AgNPs were mostly spherical with an average size of 12 nm and AuNPs with some triangular and hexagonal in shapes with an average size of 11 nm. Increase in sizes of AgNPs (Bankar et al., 2010b) and AuNPs were found on higher metal ion concentration; large particles were found varying from 30 to 60 nm and 50 to 250 nm in case of AgNPs and AuNPs, respectively (Dubey et  al., 2010). AgNPs biosynthesized by Trachyspermum ammi seeds extract, in which increase in concentration of T. ammi accelerated the reduction rate of Ag+ and affected the AgNPs particle size (Chouhan et al., 2017). A comparison of the morphologies of CuO NPs synthesized by gum karaya indicates that with an increase in the concentration of the metal precursor, the resulting CuO NPs contain a greater number of particles with distinctive changes in particle sizes. The gum networks are clearly embedded with well-separated, spherical NPs with diameters ranging from 2 to 10 nm. In the case of the 1 mM concentration of CuCl2 • 2H2O used, monodispersed NPs (7.8 ± 2.3 nm) were observed, while in the case of higher concentrations of CuCl2 • 2H2O (2 and 3 mM), the formed CuO particles size varied from 5.5 ± 2.5 to 4.8 ± 1.6 nm, respectively (Padil and Černík, 2013). Rajendran et  al. found that increasing the leaf extract concentration at the formation of ZnO and Iron NPs increases the rate of reduction and the reduction of precursor into the NPs to be optimized at 20% leaf extract concentration (Rajendran and Sengodan, 2017). UV–vis spectrum of the produced AuNPs by Macrotyloma uniflorum in different extract quantities from 0.5 to 2 mL showed a shift to shorter wavelengths, which indicates the decrease in particle size (Aromal et al., 2012). Bankar et al. (2010a,b) indicated the reaction mixtures containing

94

3.  Phytosynthesis of Nanoscale Materials

10 mg/mL of banana peel extract developed a dark brown color. With 5.0, 2.5, or 1.25 mg of banana peel extract, lighter shades of brown were obtained and the peaks were proportionately less intense. There was variation in the colors that developed when the content of the banana peel extract was decreased. When the quantity of the biological material mediating nanoparticle synthesis is increased, higher contents of the biomolecules involved in the metal reductive process are available, thereby resulting in a more intense color. Such an effect has been observed with the bark extract of Cinnamon zeylanicum and with the leaves of Cinnamon camphora (Bankar et al., 2010b). 8.2.4  Incubation Time The synthesis of NPs depends upon the rate of the reaction and the stability of the NPs depends upon the reaction time (Prasad, 2014). The earlier works done also suggested that the contact or incubation time also affects the synthesis of NPs. It is the time duration required for completion of all steps of reaction (Carrillo-López et al., 2014). A recent study by Ahmad et al. revealed that the reaction time to synthesize spherical AgNPs using Ananas comosus (pineapple) extract is an important factor indeed. In this particular case, it produced a rapid color change within 2 min. Aqueous Ag(NO)3 in the reaction medium was rapidly reduced and NPs appeared within 2 min. The reaction continued up to 5 min, but after that only a slight variation in color could be observed. The NPs produced were spherical and had a mean size of 12 nm. In a similar study by Dwivedi and Gopal, Chenopodium album leaf extract was used to produce Ag and AuNPs. During synthesize NPs appeared within 15 min and continued to form over a 2-h period. Beyond the 2-h period very few NPs were produced (Shah et al., 2015). Dubey et al. (2010) observed that in Tansy fruit mediated synthesis, the formation of AuNPs and AgNPs started within 10 min of the reaction and increase in the contact time is responsible for the sharpening of the peaks in both AuNPs and AgNPs. In addition, Veerasamy et al. stated recently that due to the instability of NPs formed, an optimum duration is required for complete nucleation and subsequent stability of NPs. Similarly, Ghoreishi et al. (2011) also showed the requirement of optimum reaction time for the stability of synthesized silver and AuNPs using Rosa damascene (Ghoreishi et al., 2011; Akhtar et al., 2013) Increasing the reaction time tended to produce particles with increasing size when Azadirachta indica leaf extract and Ag(NO)3 were combined. The reaction time was varied between 30 min and 4 h to produce a change in particle size ranging from 10 to 35 nm (Prathna et al., 2011). Due to the limited ability of plants to reduce metal ions, the efficiency of metal nanoparticle synthesis also depends on the electrochemical potential of an ion. Thus, the ability of a plant extract to effectively reduce metal ions may be significantly higher in the case of ions having a large positive electrochemical potential (for example, Ag+) than in the case of ions with a low electrochemical potential (e.g., [Ag(S2O3)2]3−; Haverkamp and Marshall, 2009).

9  APPLICATION OF NPS SYNTHESIZED IN PLANTS The pure metals in nanoparticle form are applied in the field of diagnostics, drug delivery, biosensing, antimicrobial agents, medical devices, treatment of several acute and chronic diseases malaria, hepatitis, cancer and AIDS, textiles (clothing), food industry, electronics, cosmetics, and paints (Makarov et al., 2014).



9  Application of NPs Synthesized in Plants

95

AuNPs made using the plant extract were found to be superior to the extract as hypoglycemic agents in rats for the management of diabetes mellitus (Liu et al., 2012)

9.1  Antibacterial Activity of Metal NPs The threat posed by the potential outbreak of antibiotic-resistant microbes is growing globally and demands the introduction and production of novel more advanced platforms for the study and development of more potent antimicrobial agents against multidrug-resistant strains. This antimicrobial potential is attributed to the distinctive surface chemistry, smaller size, polyvalent, and photothermic nature (Nadeem et al., 2017). The cellular membrane of bacteria and other microorganisms are negatively charged and NPs mostly impede the electrostatic flux across membranes, resulting in distorted membranes. Bactericidal activity is presumably due to changes in the structure of the bacterial cell wall as a result of interactions with embedded AgNPs, leading to increased membrane permeability and consequently death (Chung et al., 2016). AgNPs can damage the genetic material inside the bacterial cell by binding with it, resulting in inhibition of the transcription and translation process. The antibacterial property of synthesized NPs using Tribulus terrestris fruit extract was observed against clinically isolated multi-drug resistant bacteria such as Streptococcus pyogens, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus (Gopinath et al., 2012). The AgNPs biosynthesis of Premna herbacea leaf extract was tested for two bacteria, namely Shigella dysentriea and E. coli. Comparing the tested bacteria, it was found that E. coli was least effective and Shigella dysentrieae was most susceptible to the AgNPs (Kumar et al., 2013) AgNPs produced using the extract Tridax procumbens display strong antimicrobial activity against Escherichia coli, Shigella dysenteriae, and Vibrio cholera, similar to their equivalents obtained using chemical or physical methods (Dhanalakshmi and Rajendran, 2012). AgNPs obtained using Acorus calamus (Nakkala et al., 2014), Boerhaavia diffusa (Vijay Kumar et al., 2014), Tribulus terrestris (Gopinath et al., 2012), Pistacia atlantica (Sadeghi et al., 2015b), Citrus sinensis (Kaviya et al., 2011), and Cymbopogan citratus (Masurkar et al., 2011) exhibit antibacterial activity against various gram-positive and gram-negative pathogens, such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterococcus faecalis, Aeromonas hydrophila, Salmonella paratyphi, Streptococcus pyogens, Staphylococcus aureus, and Bacillus subtilis. AgNPs synthesized using Pinus thunbergii cone extracts exhibit antibacterial activity against various agricultural bacterial pathogens, such as Pseudomonas syringae, Xanthomonas oryzae, Burkholderia glumae, and Bacillus thuringiensis (Velmurugan et al., 2012). Similarly, Krishnaraj et al. (2010) reported that Acalypha indica plant leaf synthesized AgNPs effectively to control water borne pathogenic bacteria with lower concentrations of 10 lg/ml (Krishnaraj et al., 2010). AuNPs showed highest activity against gram-negative bacteria than gram-positive bacteria (Nadeem et  al., 2017). AuNPs are synthesized using diverse plant extracts such as Salix alba (Islam et al., 2015b), Solanum nigrum (Muthuvel et al., 2014), Pistacia integerrima (Islam et al., 2015a), Punica granatum (Ganeshkumar et al., 2013), Hibiscus cannabinus (Bindhu et al., 2014), and Tridax procumbens (Dhanalakshmi and Rajendran, 2012) and have been used for investigating their antimicrobial activities against different bacteria such as Salmonella typhi, Escherichia coli, Pseudomonas areuoginosa, Klebsiella pneumoniae, Vibrio cholera, and Staphylococcus aureus. Cucurbita pepo and Malva crispa leaf extract was used to synthesize spherical shaped AuNPs and showed

96

3.  Phytosynthesis of Nanoscale Materials

antibacterial activity against food spoilage pathogens (Chandran et al., 2014). ZnONPs have been widely employed for various pharmacological applications. It can be easily absorbed by negatively charged cellular membrane to contribute to efficient intracellular distribution. Therefore, it is suggested that the synthesized Zn-TAP NPs are more suitable in drug delivery processes (Kavitha et al., 2017). Significant antibacterial activity of Aloe vera leaf extract-ZnONPs was observed against extended spectrum beta lactamases positive E. coli, Pseudomonas aeruginosa, and methicillin resistant S. aureus clinical isolates exhibiting the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 2200, 2400 μg/mL and 2300, 2700 μg/mL, respectively. Those NPs with strong antimicrobial and anti-biofilm activities are envisaged as prospective nanoantibiotics, effective against the bacterial strains resilient to conventional antibiotics (Ali et al., 2016). NPs of copper have also gained importance due to their widespread application as antimicrobials. Copper NPs of various sizes ranging from 5 to 280 nm have been synthesized by using extracts prepared from Syzygium aromaticum, Tabernaemontana divaricate, Magnolia Kobus (Lee et al., 2013), Vitis vinifera, Aloe vera, Cassia alata, Centella asitica, Bifurcaria bifurcate, Gloriosa superba, and Citrus medica showing antibacterial activity and that can inhibiting the growth of pathogenic bacteria belonging to gram-positive and gram-negative genera (Kasana et al., 2016). The antibacterial activity of copper NPs synthesized using brown alga Bifurcaria bifurcata extract showed radial diameter of the inhibition zone of Enterobacter aerogenes and Staphylococcus aureus as 14 and 16 mm, respectively (Abboud et al., 2014). Shende et al. (2015) reported that the copper NPs synthesized using Citron juice from Citrus medica Linn. demonstrated a significant inhibitory activity against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Propionibacterium acnes, and Salmonella typhi (Shende et al., 2015).

9.2  Antifungal Activity of Metal NPs Most of the commercial antifungal agents have limited applications clinically but the fungicidal and antifungal mechanism of biosynthesized metallic NPs has more potential than commercial antibiotics. Subsequently, the commercial drugs induce side effects, such as renal failure, increased body temperature, nausea, liver damage, and diarrhea after using the drugs. The fungal cell wall is made up of high polymer of fatty acid and protein (Kuppusamy et al., 2016; Gardea-Torresdey et al., 2002). The plant derived AgNPs by Argimone mexicana (Singh et al., 2010a), Svensonia hyderabadensis (Linga Rao and Savithramma, 2012), and Solanus torvum (Govindaraju et al., 2010) have clearly showed the membrane damage in Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Candida sp., Curvularia lunata, and Rhizopus arrhizus damage in fungal intercellular components and finally cell function was destroyed. Nayaran and Park (2014) demonstrated the synthesis of AgNPs using Brassica rapa leaf extract and its interaction with wood-degrading fungal pathogens, such as Gloeophyllum abietinum, G. trabeum, Chaetomium globosum, and Phanerochaete sordida (Narayanan and Park, 2014). The aqueous seed extract of Abelmoschus esculentus was used to synthesized AuNPs and its antifungal activities were tested against Puccinia graminis tritci, Aspergillus flavus, Aspergillus niger, and Candida albicans. The synthesized NPs, hence, have great potential in the preparation of drugs used against fungal diseases (Jayaseelan et al., 2013). AuNPs synthesized using diverse plant extracts, such as Caesalpinia pulcherrima, Helianthus annuus (Basavegowda et al., 2012a; Liny et al., 2012), Carthamus tinctorius (Basavegowda et al., 2012b), Rivea hypocrateriformis (Godipurge et al., 2016), and Punica granatum (Ganesh Kumar et al., 2011) have been



9  Application of NPs Synthesized in Plants

97

used for investigating their antifungal activities against different bacteria such as Aspergillus flavus, Aspergillus niger, Trichophyton rubrum, and Chrysosporium indicum. Rajiv et  al. synthesized different-sized zinc oxide NPs and explored the size-dependent antifungal activity against plant fungal pathogens such as Aspergillus flavus and Aspergillus niger. At room temperature, the smaller zinc oxide NPs indeed have higher antifungal activity than larger NPs (Agarwal et al., 2017). In vitro antifungal activity of chemically synthesized copper NPs was carried out against four different plant pathogenic fungi—Phoma destructiva, Curvularia lunata, Alternaria alternata, and Fusarium oxysporum—using the disc diffusion method (Abboud et al., 2014). Copper NPs synthesized using Citron juice from Citrus medica Linn demonstrated by Shende et  al. (2015) exhibited significant inhibitory activity against plant pathogenic fungi, Fusarium culmorum, Fusarium oxysporum, and Fusarium graminearum (Shende et al., 2015).

9.3  Larvicidal Activity of Metal Nanoparticles Due to the high resistance of parasites, an alternative drug is needed for controlling the resistance strains. The plants developed metallic NPs such as silver, gold, platinum and PdNPs effectively control the malarial population in the environment and larvicidal activity against the larvae of different pathogens. The biogenic synthesis of metallic AgNPs from plant extracts have been used to suppress the number of malarial productions (Kuppusamy et al., 2016). Synthesized AgNPs using aqueous leaf extract of Euphorbia prostrata significantly inhibited the unique trypanothione reductase (TR) system of Leishmania cells (Zahir and Indira, 2015). The biolarvicidal effect (Aedes aegypti and Culex quinquefasciatus) of AgNPs was synthesized from the aqueous leaf extract of Azadirachta indica demonstrated by Poopathi et al. (2015). In addition, the activity of AgNPs synthesized using Murraya koenigii plant leaf extract against instars larvae and pupae of Anopheles stephensi and Aedes aegypti was determined. The synthesized AgNPs from M. koenigii leaf were more highly toxic than crude leaf ethanol extract in both mosquito species (Suganya et al., 2013a). Moreover, AgNPs synthesized in Nerium oleander display strong larvicidal activity against larvae of the malaria vector Anopheles stephensi (Suganya et al., 2013b). AuNPs synthesized by using leaf extract of A. vulgaris and T. cordifolia have larvicidal activity against A. aegypti larvae. The compound displaying larvicidal activity, Beta caryophyllene, was present in synthesized AuNPs, which was confirmed through 13C NMR. This compound may conjugate with gold ions and act against A. aegyptivector (Sundararajan and Ranjitha Kumari, 2017). C. citratus-synthesized AuNPs can be employed at very low concentrations to boost the control of Anopheles and Aedes larval populations in copepod-based control programs (Murugan et al., 2015b).

9.4  Antiviral Effect of Metal Nanoparticles Plant-mediated NPs are the alternative drugs for treating and controlling the growth of viral pathogens. The entry of viruses into a host is very reckless and it involves a faster translational process to multiply their colony numbers. Biosynthesis of AgNPs NPs can act as potent broad-spectrum antiviral agents to restrict virus cell functions. Suriyakalaa et al. (2013) studied the bio-AgNPs that have persuasive anti-HIV action at an early stage of ­reverse ­transcription

98

3.  Phytosynthesis of Nanoscale Materials

mechanism. The metallic NPs are strong antiviral agents and inhibit the viral entry into the host system. The biosynthesized metallic NPs have multiple binding sites to bind with gp120 of the viral membrane to control the function of the virus. The bio-based NPs act as an effective virucidal agent against the cell-free virus and the cell-associated virus. In addition, the silver and AuNPs are constantly inhibiting post-entry stages of the HIV-1 life cycle. Therefore, the metallic NPs will act as a promising antiviral drug against retro viruses (Kuppusamy et al., 2016).

9.5  Anticancer Effect of Metal Nanoparticles Cancer is an uncontrolled cell proliferation with hysterical changes of biochemical and enzymatic parameters, which is a universal property of tumor cells. The overexpression of cellular growth will be arrested and regulated with systematic cell cycle mechanisms in cancerous cells by using bio-based NPs as novel controlling agents. Also, the plant-mediated NPs have great effect against various cancer cell lines such as Hep 2, HCT 116, and HeLa cell lines. Recently, many studies have reported that plant-derived NPs have potential to control tumor cell growth. The metallic NPs have proved their novel applications in the medical field to diagnose and treat various types of cancer and other retroviral diseases. The bio-based NPs are new and have revolutionized the treatment of malignant deposits without interfering with normal cells (Kuppusamy et al., 2016). AgNPs synthesized in plants display significant cytotoxic activity against various tumor cell lines. AgNPs synthesized in Iresine herbstii were found to inhibit the survival and growth of HeLa cell lines, and AgNPs produced using Euphorbia nivulia latex extracts are toxic to the A549 cell line of human lung cancer (Valodkar et al., 2012, 2011). Green synthesized Vitex negundo AgNPs showed apoptotic changes involving nuclear condensation by PI staining in HCT15 colon cancer cells (Nakkala et al., 2014). The biogenic silver and AuNPs using Acalypha indica leaf extract were tested for their potent cytotoxic activity against MDA-MB-231, breast cancer cells. The results of the mechanistic studies indicated that silver and AuNPs induced apoptosis through caspase-3 activation and DNA fragmentation (Krishnaraj et  al., 2014). AgNPs synthesized by Syzygium cumini fruit extract were also found to destroy Dalton lymphoma cell lines under in  vitro condition (Mittal et  al., 2015). Balashanmugam et  al. (2016) demonstrated that phytosynthesized AuNPs of Cassia roxburghii extract could induce apoptosis and arrest cell growth on HepG2 cancer cell line and clearly limited toxic on normal cells but toxic in cancer cells (Balashanmugam et al., 2016). The mechanism of the observed cytotoxicity of AuNPs synthesis using Abutilon indicum leaf extract was explained on the basis of increased levels of reactive oxygen species and simultaneous reduction in cellular antioxidants, which might have caused mitochondrial membrane potential loss and DNA damage (Mata et al., 2016). The usage of AuNPs biosynthesized from D. pleiantha rhizome shows effective anti-metasatic activity against human fibrosarcoma cell line HT-1080 (Karuppaiya et al., 2013). The biosynthesized CuNPs by Eclipta prostrata leaf extract displayed considerable antioxidant capacity. Chung et  al. (2017) indicated the cytotoxicity value of synthesized CuNPs against tested HepG2 cells (Chung et al., 2017). In addition AgNPs biosynthesized by bark extract of Butea monosperma also proved to exhibit excellent cytotoxic effect on human myeloid leukemia cell line, KG-1A with IC50 value of 11.47 μg/mL (Pattanayak et al., 2017). Patra et al. biosynthesized Au and Ag nanoparticle by Butea monosperma leaf extract based drug delivery systems (DDS) using the FDA-approved anticancer drug doxorubicin and



10  Environmental Application of Metal Nanoparticles

99

­ bserved that the administrations of these DDS towards cancer cells show better therapeuo tic efficacy compared to free drug (Patra et al., 2015). AuNPs synthesized by peel extract of Punica granutum could be used for targeted drug delivery for cancer with enhanced therapeutic efficacy and minimal side effects (Ganeshkumar et al., 2013).

10  ENVIRONMENTAL APPLICATION OF METAL NANOPARTICLES Recently, nanoproducts have had an immense number of applications in day-to-day life. There are also various ecofriendly nanoproducts available in the commercial market with high efficiency, for example, as a water purifier, bone and teeth cement, facial cream and homemade products (Kouvaris et al., 2012; Kuppusamy et al., 2016). Cyamopsis tetragonoloba extracts were used recently to produce composite AgNPs that can act as a biosensor to determine ammonia, with possible applications in agriculture and biomedicine. Depending on the ammonia concentration, the distance between the NPs inside the nanocomposite changes, which affects its optical properties (Makarov et al., 2014). Catalytic activity is also ascribed to AuNPs obtained in Sesbania drummondii which may participate in the reduction of aromatic nitro compounds; for example, convert highly toxic 4-nitrophenol to 2-amino-phenol, which suggests their possible involvement in waste decontamination (Sharma et al., 2007). It is believed that both 3-nitrophenol/4-nitrophenol and the reducing agent BH4− are adsorbed on the surface of the AuNPs and the surface hydride ions are then transferred to 3-nitrophenol/4-nitrophenol thereby facilitating the reduction reaction (Majumdar et al., 2016). Platinum NPs obtained using Ocimum sanctum extracts were shown to possess a catalytic activity and may be used in the production of hydrogen fuel elements (Soundarrajan et al., 2012). PtNPs synthesized by Alchornea laxiflora bark extract has higher catalytic activity for oxidative desulphurization of model oil than acetic acid. Our results indicate that this ecofriendly, simple, and cost-effective method will find useful applications in the petroleum industry (Olajire et al., 2017). P. granatum could be used for the synthesis of cobalt-oxide NPs for photocatalytic applications. Photocatalytic activity of the NPs was evaluated by degrading Remazol Brilliant Orange 3R dye and a degradation of 78.45% was achieved using 0.5 g ­cobalt-oxide NPs for 50 min irradiation time (Bibi et al., 2017b). Both zinc oxide and iron oxide NPs biosynthesized by Sesbania grandiflora leaf extract could be used as a better source as a photocatalyst for chemical oxygen demand (of sea food industry) removal (Rajendran and Sengodan, 2017). The PtNPs prepared using dried leaf powder of Anacardium occidentale have high potential for the reduction of aromatic nitro compounds (Sheny et al., 2013). For instance, silver, silica, and platinum NPs have various applications in personal care and cosmetics and they are used as ingredients in various products, such as sunscreens, ­anti-ageing creams, toothpastes, mouthwash, hair care products, and perfumes. The silica nanomaterials are used as ingredients in various commercial products. Also, the modified silica nanomaterials are used as excellent pesticide control and it is used in a variety of nonagricultural applications (Kuppusamy et al., 2016). The produced cationic AuNPs using by Peanute leaf extract uphold the applications in gene delivery. This AuNPs can be used for efficient gene delivery (Raju et al., 2014).

100

3.  Phytosynthesis of Nanoscale Materials

11  CONCLUSION AND PERSPECTIVES Metal NPs have multiple applications in various fields of science such as disease diagnostics and treatment, electronics, catalytic, probes, imagining, remediation, and cellular transportation. Metal NPs are being synthesized through different physicochemical methods (Nadeem et  al., 2017). But biogenic reduction of the metal salt to synthesize metal nanoparticles are environmentally friendly, cost-effective, and easily scaled up for large-scale syntheses of NPs; furthermore, there is no need to use high temperature, pressure, energy, and toxic chemicals (Shankar et al., 2016). Green sources, such as plants, act as both stabilizing and reducing agents for the synthesis of shape- and size-controlled NPs (Agarwal et al., 2017). It is the best platform for syntheses of NPs, being free from toxic chemicals and providing natural capping agents for the stabilization of metal NPs (Ahmed et al., 2016). The plant metabolites are usually employed in these synthetic methods in the form of concentrated aqueous extracts of leaves, stems, flowers, fruits, seeds, barks, gum, and peel with combination of biomolecules, such as proteins, amino acids, enzymes, polysaccharides, alkaloids, tannins, phenolics, saponins, terpinoids, and vitamins (Nadeem et al., 2017; Shankar et al., 2016; Ahmed et al., 2016). The presence of biomolecules like protein, alcoholic and phenolic compounds could probably act as a stabilizer agent for the green synthesized metal NPs, and compounds like poly-phenols, carbonyl groups, flavonones, alkaloids, terpenoids, and amines act as reducing agent for NPs synthesis (Ismail et al., 2016). Biological NPs are more effective due to the attachment of biologically active components on the surface of synthesized NPs from the biological sources, such as plants (Singh et al., 2016a). The benefits of synthesis of metal NPs using plant extracts are that it is economical, energy efficient, cost effective, and protects human health and the environment leading to less waste and safer products. For the syntheses of NPs, employing plants can be advantageous over other biological entities which can overcome the time-consuming process of employing microbes and maintaining their culture which can lose their potential towards synthesis of NPs. Use of plant extracts also reduces the cost of microorganisms isolation and their culture media which enhance the cost competitive feasibility over NPs synthesis by microorganisms (Ahmed et al., 2016). Agricultural crop wastes and food industry wastes are also excellent candidates for supplying sources of plant-based biochemicals with the potential to synthesize metallic NPs and similar products (Shah et al., 2015). Many reports have been published about the syntheses of metals NPs using plant extracts like those already discussed. Massive numbers of plant species are available in nature; many of them can be excellent candidates for nanoparticle synthesis. Many researchers have developed rapid synthetic methodologies with high yields by utilizing various plant sources (Singh et al., 2016a). Control of the shape and size of metal NPs has been shown by either constraining their environmental growth or altering the functional molecules. Properties of the plant extracts, such as its concentration, metal salt concentration, reaction time, reaction solution pH, temperature and inclusion of additives of biological origin (biomatrices), significantly influence the quality, size, and morphology of the synthesized NPs (Shah et al., 2015). Of course, the reaction rate depends on the plant type and its amount. At the present time, the rate and recovery of reactions involved in the production of NPs using plant extracts are comparable with those of well-known chemical methods (Noruzi, 2015). There is a need for more studies to evaluate and understand the actual plant dependent mechanisms.

REFERENCES 101

Plant synthesized NPs have the potential to be widely used in current medical procedures involving NPs such as fluorescent labelling in immunoassays, targeted delivery of therapeutic drugs, tumor destruction via heating (hyperthermia), as antibacterial agents in bandages and delivery of antimicrobiological compounds for use as pesticides for agricultural crops (Shah et al., 2015). In future, plants will have wide perspective for the synthesis of metallic NPs in healthcare and commercial products and laboratory-scale production of metallic NPs to the extent of large-scale production. Moreover, it is possible to envision companies involved in the food industry and interested in the recycling of waste to partially pay for nanoparticle production.

References Abboud, Y., Saffaj, T., Chagraoui, A., El Bouari, A., Brouzi, K., Tanane, O., Ihssane, B., 2014. Biosynthesis, characterization and antimicrobial activity of copper oxide nanoparticles (CONPs) produced using brown alga extract (Bifurcaria bifurcata). Appl. Nanosci. 4 (5), 571–576. Abdelghany, A.M., Abdelrazek, E.M., Badr, S.I., Abdel-Aziz, M.S., Morsi, M.A., 2017. Effect of gamma-irradiation on biosynthesized gold nanoparticles using Chenopodium murale leaf extract. J. Saudi Chem. Soc. 21 (5), 528–537. Abdel-Raouf, N., Al-Enazi, N.M., Ibraheem, I.B.M., 2017. Green biosynthesis of gold nanoparticles using Galaxaura elongata and characterization of their antibacterial activity. Arab. J. Chem. 10 (Suppl 2), S3029–S3039. Abdel-Raouf, N., Alharbi, R.M., Al-Enazi, N.M., Alkhulaifi, M.M., Ibraheem, I.B.M., 2018. Rapid biosynthesis of silver nanoparticles using the marine red alga Laurencia catarinensis and their characterization. J. Basic Appl. Sci. 7 (1), 150–157. Abdul Salam, H., Sivaraj, R., Venckatesh, R., 2014. Green synthesis and characterization of zinc oxide nanoparticles from Ocimum basilicum L. var. purpurascens Benth.-Lamiaceae leaf extract. Mater. Lett. 131 (Suppl C), 16–18. Abdullah, N.I.S.B., Ahmad, M.B., Shameli, K., 2015. Biosynthesis of silver nanoparticles using Artocarpus elasticus stem bark extract. Chem. Cent. J. 9, 61. Abou El-Nour, K.M.M., Eftaiha, A.A., Al-Warthan, A., Ammar, R.A.A., 2010. Synthesis and applications of silver nanoparticles. Arab. J. Chem. 3 (3), 135–140. Ærøe Hyllested, J., Espina Palanco, M., Hagen, N., Mogensen, K.B., Kneipp, K., 2015. Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents. Beilstein J. Nanotechnol. 6, 293–299. Agarwal, H., Venkat Kumar, S., Rajeshkumar, S., 2017. A review on green synthesis of zinc oxide nanoparticles–an eco-friendly approach. Res. Effic. Technol. 3 (4), 406–413. Ahmad, N., Sharma, S., Alam, M.K., Singh, V.N., Shamsi, S.F., Mehta, B.R., Fatma, A., 2010. Rapid synthesis of silver nanoparticles using dried medicinal plant of basil. Colloids Surf. B: Biointerfaces 81 (1), 81–86. Ahmad, T., Irfan, M., Bhattacharjee, S., 2016. Parametric study on gold nanoparticle synthesis using aqueous elaise guineensis (oil palm) leaf extract: effect of precursor concentration. Procedia Eng. 148, 1396–1401. Ahmed, S., Ahmad, M., Swami, B.L., Ikram, S., 2016. A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: a green expertise. J. Adv. Res. 7 (1), 17–28. Akhtar, M.S., Swamy, M., 2015. Biosynthesis and characterization of silver nanoparticles from methanol leaf extract of Cassia didymobotyra and assessment of their antioxidant and antibacterial activities. J. Nanosci. Nanotechnol. 15 (12), 9818–9823. Akhtar, M.S., Panwar, J., Yun, Y., 2013. Biogenic synthesis of metallic nanoparticles by plant extracts. ACS Sustain. Chem. Eng. 1, 591. Aladpoosh, R., Montazer, M., 2015. The role of cellulosic chains of cotton in biosynthesis of ZnO nanorods producing multifunctional properties: Mechanism, characterizations and features. Carbohydr. Polym. 126 (Supplement C), 122–129. Alagar Yadav, S., Jebamalai Raj, A., Bahuleyan Vasantha, P., and Ramalingam, S., 2013. Synthesis of siver nanoparticles using rhizome extract of Gloriosa superba (LINN) show antibacterial activity. Indo Am. J. Pharmaceut. Res. 3 (12), 1740–1746.

102

3.  Phytosynthesis of Nanoscale Materials

Ali, K., Dwivedi, S., Azam, A., Saquib, Q., Al-Said, M.S., Alkhedhairy, A.A., Musarrat, J., 2016. Aloe vera extract functionalized zinc oxide nanoparticles as nanoantibiotics against multi-drug resistant clinical bacterial isolates. J. Colloid Interface Sci. 472 (Suppl C), 145–156. Allabashi, R., Stach, W., de la Escosura-Muñiz, A., Liste-Calleja, L., Merkoçi, A., 2008. ICP-MS: a powerful technique for quantitative determination of gold nanoparticles without previous dissolving. J. Nanopart. Res. 11 (8), 2003. Alyza, A.A., Norhidayah, M.A., 2015. Green synthesis of silver nanoparticles using Rhizhome extract of Galangal, Alpinia galanga. Malays. J. Anal. Sci. 19 (6), 1187–1193. Ambika, S., Sundrarajan, M., 2015. Antibacterial behaviour of Vitex negundo extract assisted ZnO nanoparticles against pathogenic bacteria. J. Photochem. Photobiol. B Biol. 146 (Suppl C), 52–57. Amin, M., Anwar, F., Janjua, M.R.S.A., Iqbal, M.A., Rashid, U., 2012. Green synthesis of silver nanoparticles through reduction with Solanum xanthocarpum L. Berry extract: characterization, antimicrobial and urease inhibitory activities against Helicobacter pylori. Int. J. Mol. Sci. 13 (8), 9923. Amooaghaie, R., Saeri, M.R., Azizi, M., 2015. Synthesis, characterization and biocompatibility of silver nanoparticles synthesized from Nigella sativa leaf extract in comparison with chemical silver nanoparticles. Ecotoxicol. Environ. Saf. 120 (Suppl C), 400–408. Anbuvannan, M., Ramesh, M., Viruthagiri, G., Shanmugam, N., Kannadasan, N., 2015. Anisochilus carnosus leaf extract mediated synthesis of zinc oxide nanoparticles for antibacterial and photocatalytic activities. Mater. Sci. Semicond. Process. 39 (Suppl C), 621–628. Andreescu, D., Eastman, C., Balantrapu, K., Goia, D.V., 2007. A simple route for manufacturing highly dispersed silver nanoparticles. J. Mater. Res. 22 (9), 2488–2496. Ankamwar, B., Chaudhary, M., Sastry, M., 2005a. Gold nanotriangles biologically synthesized using tamarind leaf extract and potential application in vapor sensing. Synth. React. Inorg., Met.-Org., Nano-Met. Chem. 35 (1), 19–26. Ankamwar, B., Damle, C., Ahmad, A., Sastry, M., 2005b. Biosynthesis of gold and silver nanoparticles using emblica officinalis fruit extract, their phase transfer and transmetallation in an organic solution. J. Nanosci. Nanotechnol. 5, 1665–1671. Ankanna, S., Prasada, T.N.V.K.V., Elumalai, E.K.B., Savithramma, N., 2010. Production of biogenic silver nanoparticles using Boswellia ovalifoliolata stem bark. Dig. J. Nanomater. Biostruct. 5 (2), 369–372. Antony, J.J., Nivedheetha, M., Siva, D., Pradeepha, G., Kokilavani, P., Kalaiselvi, S., Sankarganesh, A., Balasundaram, A., Masilamani, V., Achiraman, S., 2013. Antimicrobial activity of Leucas aspera engineered silver nanoparticles against Aeromonas hydrophila in infected Catla catla. Colloids Surf. B: Biointerfaces 109, 20–24. Arockiya Aarthi Rajathi, F., Parthiban, C., Ganesh Kumar, V., Anantharaman, P., 2012. Biosynthesis of antibacterial gold nanoparticles using brown alga, Stoechospermum marginatum (kützing). Spectrochim. Acta A Mol. Biomol. Spectrosc. 99 (Suppl C), 166–173. Arockiya A-Rajathi, F., Arumugam, R., Saravanan, S., Anantharaman, P., 2014. Phytofabrication of gold nanoparticles assisted by leaves of Suaeda monoica and its free radical scavenging property. J. Photochem. Photobiol. B Biol. 135 (Suppl C), 75–80. Arokiyaraj, S., Arasu, M.V., Vincent, S., Prakash, N.U., Choi, S.H., Oh, Y.-K., Choi, K.C., Kim, K.H., 2014. Rapid green synthesis of silver nanoparticles from Chrysanthemum indicum L and its antibacterial and cytotoxic effects: an in vitro study. Int. J. Nanomedicine 9, 379–388. Aromal, S.A., Vidhu, V.K., Philip, D., 2012. Green synthesis of well-dispersed gold nanoparticles using Macrotyloma uniflorum. Spectrochim. Acta A Mol. Biomol. Spectrosc. 85 (1), 99–104. Arsiya, F., Sayadi, M.H., Sobhani, S., 2017. Green synthesis of palladium nanoparticles using Chlorella vulgaris. Mater. Lett. 186 (Suppl C), 113–115. Aruna, A., Nandhini, R., Karthikeyan, V., Bose, P., 2014. Synthesis and characterization of Silver nanoparticles of Insulin Plant (Costus pictus D. Don) leaves. Asian J. Biomed. Pharm. Sci. 4 (34), 1–16. Arya, G., Kumari, R.M., Gupta, N., Kumar, A., Chandra, R., Nimesh, S., 2018. Green synthesis of silver nanoparticles using Prosopis juliflora bark extract: reaction optimization, antimicrobial and catalytic activities. Artif. Cells Nanomed. Biotechnol. 46 (5), 985–993. Asha, S., Thirunavukkarasu, P., Shanmugam, R., 2017. Green synthesis of silver nanoparticles using mirabilis jalapa aqueous extract and their antibacterial activity against respective microorganisms. J. Pharm. Technol. 10 (3), 811–817. Ashokkumar, S., Ravi, S., Kathiravan, V., Velmurugan, S., 2014. Rapid biological synthesis of silver nanoparticles using Leucas martinicensis leaf extract for catalytic and antibacterial activity. Environ. Sci. Pollut. Res. 21 (19), 11439–11446. Aswathy Aromal, S., Philip, D., 2012. Green synthesis of gold nanoparticles using Trigonella foenum-graecum and its size-dependent catalytic activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 97 (Suppl C), 1–5.

REFERENCES 103

Awwad, A., Albiss, B.A., Salem, N., 2015. Antibacterial activity of synthesised copper oxide nanoparticles using Malva sylvestris leaf extract. SMU Med. J. 2, 91–101. Azizi, S., Namvar, F., Mahdavi, M., Ahmad, M., Mohamad, R., 2013. Biosynthesis of silver nanoparticles using brown marine macroalga, Sargassum muticum aqueous extract. Mater. Des. 6 (12), 5942. Babu, S.A., Prabu, H.G., 2011. Synthesis of AgNPs using the extract of Calotropis procera flower at room temperature. Mater. Lett. 65 (11), 1675–1677. Bahuguna, D.P., Selvasundaram, P.B., Joshi, M., Kharkwal, H., 2015. Synthesis, characterization and evaluation of antibacterial efficacy, antioxidant potential of silver nanoparticle using Myrica nagi leaf extract. Int. J. Phytorem. 6, 556–563. Balashanmugam, P., Durai, P., Balakumaran, M.D., Kalaichelvan, P.T., 2016. Phytosynthesized gold nanoparticles from C. roxburghii DC. leaf and their toxic effects on normal and cancer cell lines. J. Photochem. Photobiol. B Biol. 165, 163–173. Banerjee, P., Satapathy, M., Mukhopahayay, A., Das, P., 2014. Leaf extract mediated green synthesis of silver nanoparticles from widely available Indian plants: synthesis, characterization, antimicrobial property and toxicity analysis. Bioresour. Bioprocess. 1 (1), 3. Bankar, A., Joshi, B., Kumar, A.R., Zinjarde, S., 2010a. Banana peel extract mediated novel route for the synthesis of palladium nanoparticles. Mater. Lett. 64 (18), 1951–1953. Bankar, A., Joshi, B., Ravi Kumar, A., Zinjarde, S., 2010b. Banana peel extract mediated synthesis of gold nanoparticles. Colloids Surf. B: Biointerfaces 80 (1), 45–50. Bar, H., Bhui, D.K., Sahoo, G.P., Sarkar, P., De, S.P., Misra, A., 2009a. Green synthesis of silver nanoparticles using latex of Jatropha curcas. Colloids Surf. A Physicochem. Eng. Asp. 339 (1), 134–139. Bar, H., Bhui, D.K., Sahoo, G.P., Sarkar, P., Pyne, S., Misra, A., 2009b. Green synthesis of silver nanoparticles using seed extract of Jatropha curcas. Colloids Surf. A Physicochem. Eng. Asp. 348 (1), 212–216. Barua, S., Konwarh, R., Bhattacharya, S.S., Das, P., Devi, K.S.P., Maiti, T.K., Mandal, M., Karak, N., 2013. Nonhazardous anticancerous and antibacterial colloidal ‘green’ silver nanoparticles. Colloids Surf. B: Biointerfaces 105 (Suppl C), 37–42. Basavegowda, N., Divya, T.K., Malakar, B., Krishnamurthy, N.B., Dinesh, R., Negrila, C.C., Predoi, D., 2012a. Phytosynthesis of gold nanoparticles using Caesalpinia pulcherrima (peacock flower) flower extract and evaluation of their antimicrobial activities. Dig J Nanomater Biostruct. 7 (3), 899–905. Basavegowda, N., Malakar, B., Divya, T.K., Krishnamurthy, N.B., Liny, P., Dinesh, R., Iconaru, S.L., Carmen, C., 2012b. Synthesis of plant mediated gold nanoparticles using flower extracts of Carthamus tinctorius L. (safflower) and evaluation of their biological activities. J. Biotechnol. Biomat. 7 (3), 1289–1295. Baskaralingam, V., Sargunar, C.G., Lin, Y.C., Chen, J.C., 2012. Green synthesis of silver nanoparticles through Calotropis gigantea leaf extracts and evaluation of antibacterial activity against Vibrio alginolyticus. Nanotechnol. Dev. 2 (3), 12–16. Benakashani, F., Allafchian, A.R., Jalali, S.A.H., 2016. Biosynthesis of silver nanoparticles using Capparis spinosa L. leaf extract and their antibacterial activity. Karbala Int. J. Mod. Sci. 2 (4), 251–258. Bhattacharjee, S., 2016. DLS and zeta potential–what they are and what they are not? J. Control. Release 235, 337–351. Bhau, B.S., Ghosh, S., Puri, S., Borah, B., Sarmah, D.K., Khan, R., 2015. Green synthesis of gold nanoparticles from the leaf extract of Nepenthes khasiana and antimicrobial assay. Adv. Mater. Lett. 6 (1), 55–58. Bibi, I., Kamal, S., Ahmed, A., Iqbal, M., Nouren, S., Jilani, K., Nazar, N., Amir, M., Abbas, A., Ata, S., Majid, F., 2017a. Nickel nanoparticle synthesis using Camellia sinensis as reducing and capping agent: growth mechanism and photo-catalytic activity evaluation. Int. J. Biol. Macromol. 103 (Suppl C), 783–790. Bibi, I., Nazar, N., Iqbal, M., Kamal, S., Nawaz, H., Nouren, S., Safa, Y., Jilani, K., Sultan, M., Ata, S., Rehman, F., Abbas, M., 2017b. Green and eco-friendly synthesis of cobalt-oxide nanoparticle: characterization and photo-­ catalytic activity. Adv. Powder Technol. 28 (9), 2035–2043. Bindhu, M.R., Sathe, V., Umadevi, M., 2013. Synthesis, characterization and SERS activity of biosynthesized silver nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 115, 409–415. Bindhu, M.R., Vijaya Rekha, P., Umamaheswari, T., Umadevi, M., 2014. Antibacterial activities of Hibiscus cannabinus stem-assisted silver and gold nanoparticles. Mater. Lett. 131 (Suppl C), 194–197. Brumbaugh, A.D., Cohen, K.A., Angelo, S.K.S., 2014. Ultrasmall copper nanoparticles synthesized with a plant tea reducing agent. ACS Sustain. Chem. Eng. 2 (8), 1933–1939. Caroling, G., Nithya Priyadharshini, M., Vinodhini, E., Mercy Ranjitham, A., Shanthi, P., 2015. Biosynthesis of copper nanoparticles using aqueous guava extract characterisation and study of antibacterial effects. IJPBS 5 (2), 25–43.

104

3.  Phytosynthesis of Nanoscale Materials

Carrillo-López, M., Zavaleta-Mancera, A., Vilchis-Nestor, A., Soto-Hernández, R.M., Arenas-Alatorre, J., TrejoTéllez, L.I., Gómez-Merino, F., 2014. Biosynthesis of silver nanoparticles using Chenopodium ambrosioides. J. Nanomater. 2014, 9. Castro, L., Blázquez, M.L., Muñoz, J.A., González, F., García-Balboa, C., Ballester, A., 2011. Biosynthesis of gold nanowires using sugar beet pulp. Process Biochem. 46 (5), 1076–1082. Castro, L., Blázquez, M.L., Muñoz, J., González, F., Ballester, A., 2013. Biological synthesis of metallic nanoparticles using algae. IET Nanobiotechnol. 7 (3), 109–116. Chandran, S.P., Chaudhary, M., Pasricha, R., Ahmad, A., Sastry, M., 2006. Synthesis of gold nanotriangles and silver nanoparticles using Aloe vera plant extract. Biotechnol. Prog. 22 (2), 577–583. Chandran, K., Song, S., Yun, S.-I., 2014. Effect of size and shape controlled biogenic synthesis of gold nanoparticles and their mode of interactions against food borne bacterial pathogens. Arab. J. Chem. https://doi.org/10.1016/j. arabjc.2014.11.041. Cheloni, G., Marti, E., Slaveykova, V.I., 2016. Interactive effects of copper oxide nanoparticles and light to green alga Chlamydomonas reinhardtii. Aquat. Toxicol. 170 (Suppl C), 120–128. Chen, X., Mao, S.S., 2007. Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications. Chem. Rev. 107 (7), 2891–2959. Chouhan, N., Ameta, R., Meena, R.K., 2017. Biogenic silver nanoparticles from Trachyspermum ammi (Ajwain) seeds extract for catalytic reduction of p-nitrophenol to p-aminophenol in excess of NaBH4. J. Mol. Liq. 230 (Suppl C), 74–84. Chung, I.-M., Park, I., Seung-Hyun, K., Thiruvengadam, M., Rajakumar, G., 2016. Plant-mediated synthesis of silver nanoparticles: their characteristic properties and therapeutic applications. Nanoscale Res. Lett. 11 (1), 40. Chung, I.-M., Abdul Rahuman, A., Marimuthu, S., Kirthi, A.V., Anbarasan, K., Padmini, P., Rajakumar, G., 2017. Green synthesis of copper nanoparticles using Eclipta prostrata leaves extract and their antioxidant and cytotoxic activities. Exp. Ther. Med. 14 (1), 18–24. Coccia, F., Tonucci, L., Bosco, D., Bressan, M., d'Alessandro, N., 2012. One-pot synthesis of lignin-stabilised platinum and palladium nanoparticles and their catalytic behaviour in oxidation and reduction reactions. Green Chem. 14 (4), 1073–1078. Cruz, D., Falé, P.L., Mourato, A., Vaz, P.D., Luisa Serralheiro, M., Lino, A.R.L., 2010. Preparation and physicochemical characterization of Ag nanoparticles biosynthesized by Lippia citriodora (Lemon Verbena). Colloids Surf. B: Biointerfaces 81 (1), 67–73. Daisy, P., Saipriya, K., 2012. Biochemical analysis of Cassia fistula aqueous extract and phytochemically synthesized gold nanoparticles as hypoglycemic treatment for diabetes mellitus. Int. J. Nanomedicine 7, 1189–1202. Das, J., Velusamy, P., 2014. Catalytic reduction of methylene blue using biogenic gold nanoparticles from Sesbania grandiflora L. J. Taiwan Inst. Chem. Eng. 45 (5), 2280–2285. Das, R.K., Gogoi, N., Bora, U., 2011. Green synthesis of gold nanoparticles using Nyctanthes arbortristis flower extract. Bioprocess Biosyst. Eng. 34 (5), 615–619. Das, S., Das, J., Samadder, A., Bhattacharyya, S.S., Das, D., Khuda-Bukhsh, A.R., 2013. Biosynthesized silver nanoparticles by ethanolic extracts of Phytolacca decandra, Gelsemium sempervirens, Hydrastis canadensis and Thuja occidentalis induce differential cytotoxicity through G2/M arrest in A375 cells. Colloids Surf. B: Biointerfaces 101, 325–336. Dash, S.S., Majumdar, R., Sikder, A.K., Bag, B.G., Patra, B.K., 2014. Saraca indica bark extract mediated green synthesis of polyshaped gold nanoparticles and its application in catalytic reduction. Appl. Nanosci. 4 (4), 485–490. David, L., Moldovan, B., Vulcu, A., Olenic, L., Perde-Schrepler, M., Fischer-Fodor, E., Florea, A., Crisan, M., Chiorean, I., Clichici, S., Filip, G.A., 2014. Green synthesis, characterization and anti-inflammatory activity of silver nanoparticles using European black elderberry fruits extract. Colloids Surf. B: Biointerfaces 122 (Suppl C), 767–777. de Aragão, A.P., de Oliveira, T.M., Quelemes, P.V., Perfeito, M.L.G., Araújo, M.C., Santiago, J.D.A.S., Cardoso, V.S., Quaresma, P., de Souza de Almeida Leite, J.R., da Silva, D.A., 2016. Green synthesis of silver nanoparticles using the seaweed Gracilaria birdiae and their antibacterial activity. Arab. J. Chem. https://doi.org/10.1016/j. arabjc.2016.04.014. de Matos, R.A., Cordeiro, T.D.S., Samad, R.E., Vieira, N.D., Courrol, L.C., 2011. Green synthesis of stable silver nanoparticles using Euphorbia milii latex. Colloids Surf. A Physicochem. Eng. Asp. 389 (1), 134–137. Delma, B.T., Vijila, B., Jaya Rajan, M., 2016. Green synthesis of copper and lead nanoparticles using zingiberofficinale stemextract. Int. J. Sci. Res. Publ. 6 (11), 134–137. Dhanalakshmi, T., Rajendran, S., 2012. Synthesis of silver nanoparticles using Tridax procumbens and its antimicrobial activity. Arch. Appl. Sci. Res. 4 (3), 1289–1293.

REFERENCES 105

Dhas, T.S., Kumar, V.G., Karthick, V., Govindaraju, K., Shankara Narayana, T., 2014. Biosynthesis of gold nanoparticles using Sargassum swartzii and its cytotoxicity effect on HeLa cells. Spectrochim. Acta A Mol. Biomol. Spectrosc. 133 (Suppl C), 102–106. Diallo, A., Beye, A.C., Doyle, T.B., Park, E., Maaza, M., 2015. Green synthesis of Co3O4 nanoparticles via Aspalathus linearis: physical properties. Green Chem. Lett. Rev. 8 (3–4), 30–36. Dobrucka, R., Długaszewska, J., 2016. Biosynthesis and antibacterial activity of ZnO nanoparticles using Trifolium pratense flower extract. Saudi J. Biol. Sci. 23 (4), 517–523. Dong, C., Zhang, X., Cai, H., Cao, C., 2016. Green synthesis of biocompatible silver nanoparticles mediated by Osmanthus fragrans extract in aqueous solution. Int. J. Light Electron Opt. 127 (22), 10378–10388. Dong, C., Cao, C., Zhang, X., Zhan, Y., Wang, X., Yang, X., Zhou, K., Xiao, X., Yuan, B., 2017. Wolfberry fruit (Lycium barbarum) extract mediated novel route for the green synthesis of silver nanoparticles. Int. J. Light Electron Opt. 130 (Suppl C), 162–170. Dubey, M., Bhadauria, S., Kushwah, B., 2009. Green synthesis of nanosilver particles from extract of Eucalyptus hybrida (safeda) leaf. Dig J Nanomater Biostruct 4 (3), 537–543. Dubey, S.P., Lahtinen, M., Sillanpää, M., 2010. Green synthesis and characterizations of silver and gold nanoparticles using leaf extract of Rosa rugosa. Colloids Surf. A Physicochem. Eng. Asp. 364 (1), 34–41. Edison, T.J.I., Sethuraman, M.G., 2012. Instant green synthesis of silver nanoparticles using Terminalia chebula fruit extract and evaluation of their catalytic activity on reduction of methylene blue. Process Biochem. 47 (9), 1351–1357. Elavazhagan, T., Arunachalam, K.D., 2011. Memecylon edule leaf extract mediated green synthesis of silver and gold nanoparticles. Int. J. Nanomedicine 6, 1265–1278. Elango, G., Roopan, S.M., 2015. Green synthesis, spectroscopic investigation and photocatalytic activity of lead nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 139 (Supplement C), 367–373. El-Kassas, H.Y., El-Sheekh, M.M., 2014. Cytotoxic activity of biosynthesized gold nanoparticles with an extract of the red seaweed corallina officinalis on the MCF-7 human breast cancer cell line. Asian Pac. J. Cancer Prev. 15 (10), 4311–4317. Elumalai, K., Velmurugan, S., 2015. Green synthesis, characterization and antimicrobial activities of zinc oxide nanoparticles from the leaf extract of Azadirachta indica (L.). Appl. Surf. Sci. 345 (Suppl C), 329–336. Elumalai, E., Prasad, T., Hemachandran, J., Therasa, S.V., Thirumalai, T., David, E., 2010. Extracellular synthesis of silver nanoparticles using leaves of Euphorbia hirta and their antibacterial activities. J. Pharm. Sci. Res. 2, 549–554. Fazlzadeh, M., Khosravi, R., Zarei, A., 2017. Green synthesis of zinc oxide nanoparticles using Peganum harmala seed extract, and loaded on Peganum harmala seed powdered activated carbon as new adsorbent for removal of Cr(VI) from aqueous solution. Ecol. Eng. 103 (Part A), 180–190. Franco-Romano, M., Gil, M.L.A., Palacios-Santander, J.M., Delgado-Jaén, J.J., Naranjo-Rodríguez, I., HidalgoHidalgo de Cisneros, J.L., Cubillana-Aguilera, L.M., 2014. Sonosynthesis of gold nanoparticles from a geranium leaf extract. Ultrason. Sonochem. 21 (4), 1570–1577. Fu, L., Fu, Z., 2015. Plectranthus amboinicus leaf extract–assisted biosynthesis of ZnO nanoparticles and their photocatalytic activity. Ceram. Int. 41 (2, Part A), 2492–2496. Ganesan, R.M., Gurumallesh Prabu, H., 2015. Synthesis of gold nanoparticles using herbal Acorus calamus rhizome extract and coating on cotton fabric for antibacterial and UV blocking applications. Arab. J. Chem. https://doi. org/10.1016/j.arabjc.2014.12.017. Ganesh Kumar, V., Dinesh Gokavarapu, S., Rajeswari, A., Stalin Dhas, T., Karthick, V., Kapadia, Z., Shrestha, T., Barathy, I.A., Roy, A., Sinha, S., 2011. Facile green synthesis of gold nanoparticles using leaf extract of antidiabetic potent Cassia auriculata. Colloids Surf. B: Biointerfaces 87 (1), 159–163. Ganeshkumar, M., Sathishkumar, M., Ponrasu, T., Dinesh, M.G., Suguna, L., 2013. Spontaneous ultra fast synthesis of gold nanoparticles using Punica granatum for cancer targeted drug delivery. Colloids Surf. B: Biointerfaces 106 (Suppl C), 208–216. Gardea-Torresdey, J.L., Parsons, J.G., Gomez, E., Peralta-Videa, J., Troiani, H.E., Santiago, P., Yacaman, M.J., 2002. Formation and growth of Au nanoparticles inside live alfalfa plants. Nano Lett. 2 (4), 397–401. Gardea-Torresdey, J.L., Gomez, E., Peralta-Videa, J.R., Parsons, J.G., Troiani, H., Jose-Yacaman, M., 2003. Alfalfa sprouts: a natural source for the synthesis of silver nanoparticles. Langmuir 19 (4), 1357–1361. Gawade, V.V., Gavade, N.L., Shinde, H.M., Babar, S.B., Kadam, A.N., Garadkar, K.M., 2017. Green synthesis of ZnO nanoparticles by using Calotropis procera leaves for the photodegradation of methyl orange. J. Mater. Sci. Mater. Electron. 28 (18), 14033–14039.

106

3.  Phytosynthesis of Nanoscale Materials

Geetha, A., Sakthivel, R., Mallika, J., Kannusamy, R., Rajendran, R., 2016. Green synthesis of antibacterial Zinc Oxide nanoparticles using biopolymer azadirachta indica gum. Orient. J. Chem. 32, 955–963. Gengan, R.M., Anand, K., Phulukdaree, A., Chuturgoon, A., 2013. A549 lung cell line activity of biosynthesized silver nanoparticles using Albizia adianthifolia leaf. Colloids Surf. B: Biointerfaces 105, 87–91. Ghaffari-Moghaddam, M., Hadi-Dabanlou, R., 2014. Plant mediated green synthesis and antibacterial activity of silver nanoparticles using Crataegus douglasii fruit extract. J. Ind. Eng. Chem. 20 (2), 739–744. Ghodake, G.S., Deshpande, N.G., Lee, Y.P., Jin, E.S., 2010. Pear fruit extract-assisted room-temperature biosynthesis of gold nanoplates. Colloids Surf. B: Biointerfaces 75 (2), 584–589. Ghoreishi, S.M., Behpour, M., Khayatkashani, M., 2011. Green synthesis of silver and gold nanoparticles using Rosa damascena and its primary application in electrochemistry. Physica E 44 (1), 97–104. Ghosh, S., Patil, S., Ahire, M., Kitture, R., Kale, S., Pardesi, K., 2012. Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents. Int. J. Nanomed. 7, 483–496. Ghosh, S., Chopade, A.B., Parihar, V.S., Banerjee, K., Kamble, N., Bellare, J., Chopde, B., 2016. Dioscorea oppositifolia mediated synthesis of gold and silver nanoparticles with catalytic activity. J. Nanomed. Nanotechnol. 7 (398), 2–7. Gnanajobitha, G., Paulkumar, K., Vanaja, M., Rajeshkumar, S., Malarkodi, C., Annadurai, G., Kannan, C., 2013a. Fruit-mediated synthesis of silver nanoparticles using Vitis vinifera and evaluation of their antimicrobial efficacy. J Nanostructure Chem 3 (1), 67. Gnanajobitha, G., Paulkumar, K., Vanaja, M., Shanmugam, R., Chelladurai, M., Gurusamy, A., Kannan, C., 2013b. Fruit-mediated synthesis of silver nanoparticles using Vitis vinifera and evaluation of their antimicrobial efficacy. J. Nanostruct. Chemistry 3, 67. Gnanajobitha, G., Vanaja, M., Paulkumar, K., Shanmugam, R., Chelladurai, M., Gurusamy, A., Kannan, C., 2013c. Green synthesis of silver nanoparticles using millingtonia hortensis and evaluation of their antimicrobial efficacy. Asian Pac. J. Trop. Biomed. 3, 58–63. Godipurge, S.S., Yallappa, S., Biradar, N.J., Biradar, J.S., Dhananjaya, B.L., Hegde, G., Jagadish, K., Hegde, G., 2016. A facile and green strategy for the synthesis of Au, Ag and Au–Ag alloy nanoparticles using aerial parts of R. hypocrateriformis extract and their biological evaluation. Enzym. Microb. Technol. 95 (Suppl C), 174–184. Gogoi, S.J., 2013. Green synthesis of silver nanoparticles from leaves extract of ethnomedicinal plants Pogostemon benghalensis (B) O. Ktz. Adv. Appl. Sci. Res. 4 (4), 274–278. Gogoi, N., Babu, P.J., Mahanta, C., Bora, U., 2015. Green synthesis and characterization of silver nanoparticles using alcoholic flower extract of Nyctanthes arbortristis and in vitro investigation of their antibacterial and cytotoxic activities. Mater. Sci. Eng. C 46 (Suppl C), 463–469. Gondwal, M., Pant, G.J.N., 2013. Biological evaluation and green synthesis of silver nanoparticles using aqueous extract of Calotropis procera. Int. J. Pharm. Bio. Sci. 4 (4), 635–643. Gopinath, V., Mubarak Ali, D., Priyadarshini, S., Priyadharsshini, N.M., Thajuddin, N., Velusamy, P., 2012. Biosynthesis of silver nanoparticles from Tribulus terrestris and its antimicrobial activity: a novel biological approach. Colloids Surf. B: Biointerfaces 96, 69–74. Gopinath, M., Subbaiya, R., Masilamani Selvam, M., Suresh, D., 2014. Synthesis of copper nanoparticles from Nerium oleander. Leaf aqueous extract and its antibacterial activity. Appl. Sci. 3 (9), 814–818. Gopinath, K., Kumaraguru, S., Bhakyaraj, K., Thirumal, S., Arumugam, A., 2016. Eco-friendly synthesis of TiO2, Au and Pt doped TiO2 nanoparticles for dye sensitized solar cell applications and evaluation of toxicity. Superlattice. Microst. 92, 100–110. Govindaraju, K., Selvaraj, T., Kiruthiga, V., Singaravelu, G., 2010. Biogenic silver nanoparticles by Solanum torvum and their promising antimicrobial activity. J. Biopestic. 3, 394–399. Gul, S., Ismail, M., Khan, M.I., Khan, S.B., Asiri, A.M., Rahman, I.U., Khan, M.A., Kamboh, M.A., 2016. Novel synthesis of silver nanoparticles using melon aqueous extract and evaluation of their feeding deterrent activity against housefly Musca domestica. Asian Pac. J. Trop. Dis. 6 (4), 311–316. Guo, M., Li, W., Yang, F., Liu, H., 2015. Controllable biosynthesis of gold nanoparticles from a Eucommia ulmoides bark aqueous extract. Spectrochim. Acta A Mol. Biomol. Spectrosc. 142 (Suppl C), 73–79. Gupta, D., Chauhan, P., 2017. Green synthesis of silver nanoparticles involving extract of plants of different taxonomic groups. J. Nanomed. Res. 5 (2). Hariprasad, S., Susheela Bai, G., Santhoshkumar, J., Madhu, C., Sravani, D., 2016. Greensynthesis of copper nanoparticles by arevalanata leaves extract and their anti microbial activites. Int. J. ChemTech Res. 9 (2), 98–105.

REFERENCES 107

Haverkamp, R.G., Marshall, A.T., 2009. The mechanism of metal nanoparticle formation in plants: limits on accumulation. J. Nanopart. Res. 11 (6), 1453–1463. Heera, P., Shanmugam, S., Ramachandran, J., 2015. Green synthesis of copper nanoparticle using Gymnema sylvestre by different solvent extract. Int. J. Curr. Res. Acad. Rev. 3 (10), 268–275. Herzing, A.A., Watanabe, M., Edwards, J.K., Conte, M., Tang, Z.-R., Hutchings, G.J., Kiely, C.J., 2008. Energy dispersive X-ray spectroscopy of bimetallic nanoparticles in an aberration corrected scanning transmission electron microscope. Faraday Discuss. 138 (0), 337–351. Hong, G.-B., Jiang, C.-J., 2017. Synthesis of SnO2 nanoparticles using extracts from Litsea cubeba fruits. Mater. Lett. 194 (Suppl C), 164–167. Huang, H., Yang, X., 2004. Synthesis of polysaccharide-stabilized gold and silver nanoparticles: a green method. Carbohydr. Res. 339 (15), 2627–2631. Hudlikar, M., Joglekar, S., Dhaygude, M., Kodam, K., 2012. Green synthesis of TiO2 nanoparticles by using aqueous extract of Jatropha curcas L. latex. Mater. Lett. 75 (Suppl. C), 196–199. Iravani, S., Zolfaghari, B., 2013. Green Synthesis of silver nanoparticles using Pinus eldarica bark extract. Bio Med Res. Int. 2013, 5. Islam, N.U., Jalil, K., Shahid, M., Muhammad, N., Rauf, A., 2015a. Pistacia integerrima gall extract mediated green synthesis of gold nanoparticles and their biological activities. Arab. J. Chem. https://doi.org/10.1016/j. arabjc.2015.02.014. Islam, N.U., Jalil, K., Shahid, M., Rauf, A., Muhammad, N., Khan, A., Shah, M.R., Khan, M.A., 2015b. Green synthesis and biological activities of gold nanoparticles functionalized with Salix alba. Arab. J. Chem. https://doi. org/10.1016/j.arabjc.2015.06.025. Islam, N.U., Khan, I., Rauf, A., Muhammad, N., Shahid, M., Shah, M.R., 2015c. Antinociceptive, muscle relaxant and sedative activities of gold nanoparticles generated by methanolic extract of Euphorbia milii. BMC Complement. Altern. Med. 15, 160. Ismail, M., Gul, S., Khan, M., Khan, M., 2016. Plant mediated green synthesis of anti-microbial silver nanoparticles—a review on recent trends. 5, 119–135. Ivashchenko, O., Gapiński, J., Peplińska, B., Przysiecka, Ł., Zalewski, T., Nowaczyk, G., Jarek, M., MarcinkowskaGapińska, A., Jurga, S., 2017. Self-organizing silver and ultrasmall iron oxide nanoparticles prepared with ginger rhizome extract: characterization, biomedical potential and microstructure analysis of hydrocolloids. Mater. Des. 133 (Suppl C), 307–324. Jafarirad, S., Mehrabi, M., Divband, B., Kosari-Nasab, M., 2016. Biofabrication of zinc oxide nanoparticles using fruit extract of Rosa canina and their toxic potential against bacteria: a mechanistic approach. Mater. Sci. Eng. C 59 (Suppl C), 296–302. Jagtap, U.B., Bapat, V.A., 2013. Green synthesis of silver nanoparticles using Artocarpus heterophyllus Lam. seed extract and its antibacterial activity. Ind. Crop. Prod. 46, 132–137. Jain, D., Daima, H., Kachhwala, S., Kothari, S., 2009. Synthesis of plant-mediated silver nanoparticles using papaya fruit extract and evaluation of their anti microbial activities. Dig J Nanomater Biostruct 4, 723–727. Jamdagni, P., Khatri, P., Rana, J.S., 2018. Green synthesis of zinc oxide nanoparticles using flower extract of Nyctanthes arbor-tristis and their antifungal activity. J. King Saud Univ. Sci. 30 (2), 168–175. Jayakumarai, G., Gokulpriya, C., Sudhapriya, R., Sharmila, G., Muthukumaran, C., 2015. Phytofabrication and characterization of monodisperse copper oxide nanoparticles using Albizia lebbeck leaf extract. Appl. Nanosci. 5 (8), 1017–1021. Jayaseelan, C., Ramkumar, R., Rahuman, A.A., Perumal, P., 2013. Green synthesis of gold nanoparticles using seed aqueous extract of Abelmoschus esculentus and its antifungal activity. Ind. Crop. Prod. 45 (Suppl C), 423–429. Jeyaraj, M., Rajesh, M., Arun, R., Mubarak Ali, D., Sathishkumar, G., Sivanandhan, G., Dev, G.K., Manickavasagam, M., Premkumar, K., Thajuddin, N., Ganapathi, A., 2013. An investigation on the cytotoxicity and caspase-­ mediated apoptotic effect of biologically synthesized silver nanoparticles using Podophyllum hexandrum on human cervical carcinoma cells. Colloids Surf. B: Biointerfaces 102, 708–717. Jiale, H., Qingbiao, L., Daohua, S., Yinghua, L., Yuanbo, S., Xin, Y., Huixuan, W., Yuanpeng, W., Wenyao, S., Ning, H., Jinqing, H., Cuixue, C., 2007. Biosynthesis of silver and gold nanoparticles by novel sundried Cinnamomum camphora leaf. Nanotechnology 18 (10), 105104. Joel, C., Sheik Muhideen Badhusha, M., 2016. Green synthesis of ZnO nanoparticles using Phyllanthus embilica stem extract and their antibacterial activity. Pharm. Lett. 8 (11), 218–223. Joglekar, S., Kodam, K., Dhaygude, M., Hudlikar, M., 2011. Novel route for rapid biosynthesis of lead nanoparticles using aqueous extract of Jatropha curcas L. latex. Mater. Lett. 65 (19), 3170–3172.

108

3.  Phytosynthesis of Nanoscale Materials

Justin, P.J.S., Finub, J.S., Narayanan, A., 2012. Synthesis of silver nanoparticles using Piper longum leaf extracts and its cytotoxic activity against Hep-2 cell line. Colloids Surf. B: Biointerfaces 91, 212–214. Kadukova, J., 2016. Surface sorption and nanoparticle production as a silver detoxification mechanism of the freshwater alga Parachlorella kessleri. Bioresour. Technol. 216, 406–413. Kalaiselvi, A., Roopan, S.M., Madhumitha, G., Ramalingam, C., Elango, G., 2015. Synthesis and characterization of palladium nanoparticles using Catharanthus roseus leaf extract and its application in the photo-catalytic degradation. Spectrochim. Acta A Mol. Biomol. Spectrosc. 135 (Suppl C), 116–119. Kaliamurthi, S., Ramanathan, Selvaraj, G., 2011. Green synthesis of silver nanoparticles by using stem derived callus extract of Bitter apple. Dig J Nanomater Biostruct 6, 1019–1024. Kalpana, D., Han, J.H., Park, W.S., Lee, S.M., Wahab, R., Lee, Y.S., 2014. Green biosynthesis of silver nanoparticles using Torreya nucifera and their antibacterial activity. Arab. J. Chem. https://doi.org/10.1016/j. arabjc.2014.08.016. Kamyar, S., Ahmad, M., Almulla, E., Ibrahim, N., Shabanzadeh, P., Rustaiyan, A., Abdollahi, Y., Bagheri, S., Abdolmohammadi, S., Usman, M., Zidan, M., 2012. Green biosynthesis of silver nanoparticles using Callicarpa maingayi stem bark extraction. Molecules 17, 8506–8517. Kandasamy, K., Alikunhi, N.M., Manickaswami, G., Nabikhan, A., Ayyavu, G., 2013. Synthesis of silver nanoparticles by coastal plant Prosopis chilensis (L.) and their efficacy in controlling vibriosis in shrimp Penaeus monodon. Appl. Nanosci. 3 (1), 65–73. Kannan, R.R.R., Stirk, W.A., Van Staden, J., 2013. Synthesis of silver nanoparticles using the seaweed Codium capitatum P.C. Silva (Chlorophyceae). S. Afr. J. Bot. 86 (Suppl. C), 1–4. Kanniah, P., Gnanadhas, G., Mahendran, V., Manickam, P., Gurusamy, A., 2017. Green synthesis of silver nanoparticle and silver based chitosan bionanocomposite using stem extract of Saccharum officinarum and assessment of its antibacterial activity. Adv. Nat. Sci. Nanosci. Nanotechnol. 8 (3). Karkaj, O.S., Salouti, M., Zanjani, R.S., Derakhshan, F.K., 2013. Extracellular deposition of silver nanoparticles by Bacillus megaterium. Synth. React. Inorg., Met.-Org., Nano-Met. Chem. 43 (7), 903–906. Karunakaran, G., Jagathambal, M., Venkatesh, M., Suresh Kumar, G., Kolesnikov, E., Dmitry, A., Gusev, A., Kuznetsov, D., 2017. Hydrangea paniculata flower extract-mediated green synthesis of MgNPs and AgNPs for health care applications. Powder Technol. 305 (Suppl. C), 488–494. Karuppaiya, P., Satheeshkumar, E., Chao, W.-T., Kao, L.-Y., Chen, E.C.-F., Tsay, H.-S., 2013. Anti-metastatic activity of biologically synthesized gold nanoparticles on human fibrosarcoma cell line HT-1080. Colloids Surf. B: Biointerfaces 110 (Suppl. C), 163–170. Kasana, R.C., Panwar, N.R., Kaul, R.K., Kumar, P., 2016. Copper nanoparticles in agriculture: biological synthesis and antimicrobial activity. In: Ranjan, S., Dasgupta, N., Lichtfouse, E. (Eds.), Nanoscience in Food and Agriculture 3. Springer International Publishing, Cham, pp. 129–143. Kashif, A., Shumaila, M., Robina, S., 2017. Green synthesis of copper nanoparticles by using plant leaf extract as reductant. Adv. Biores. 8 (1), 12–16. Kasthuri, J., Kathiravan, K., Rajendiran, N., 2009a. Phyllanthin-assisted biosynthesis of silver and gold nanoparticles: a novel biological approach. J. Nanopart. Res. 11 (5), 1075–1085. Kasthuri, J., Veerapandian, S., Rajendiran, N., 2009b. Biological and synthesis of silver and gold nanoparticles using apiin as reducing agent. Colloids Surf. B: Biointerfaces 68, 55–60. Kathiravan, V., Ravi, S., Ashokkumar, S., 2014. Synthesis of silver nanoparticles from Melia dubia leaf extract and their in vitro anticancer activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 130, 116–121. Kathiraven, T., Sundaramanickam, A., Shanmugam, N., Balasubramanian, T., 2015. Green synthesis of silver nanoparticles using marine algae Caulerpa racemosa and their antibacterial activity against some human pathogens. Appl. Nanosci. 5 (4), 499–504. Kaur, P., Thakur, R., Chaudhury, A., 2016. Biogenesis of copper nanoparticles using peel extract of Punica granatum and their antimicrobial activity against opportunistic pathogens. Green Chem. Lett. Rev. 9 (1), 33–38. Kavitha, S., Dhamodaran, M., Prasad, R., Ganesan, M., 2017. Synthesis and characterisation of zinc oxide nanoparticles using terpenoid fractions of Andrographis paniculata leaves. Int. Nano Lett. 7 (2), 141–147. Kaviya, S.S.J., Viswanathan, B., 2011. Green synthesis of silver nanoparticles using Polyalthia longifolia leaf extract along with D-sorbitol. J. Nanotechnol. 2011, 1–5. Kaviya, S., Santhanalakshmi, J., Viswanathan, B., Muthumary, J., Srinivasan, K., 2011. Biosynthesis of silver nanoparticles using Citrus sinensis peel extract and its antibacterial activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 79 (3), 594–598.

REFERENCES 109

Kaviya, S., Santhanalakshmi, J., Viswanathan, B., 2012. Biosynthesis of silver nano-flakes by Crossandra infundibuliformis leaf extract. Mater. Lett. 67 (1), 64–66. Kelly, K.L., Coronado, E., Zhao, L.L., Schatz, G.C., 2003. The optical properties of metal nanoparticles: the influence of size, shape, and dielectric environment. J. Phys. Chem. B 107 (3), 668–677. Kesharwani, J., Yoon, K.Y., Hwang, J., Rai, M., 2009. Phytofabrication of silver nanoparticles by leaf extract of datura metel: hypothetical mechanism involved in synthesis. J. Bionanosci. 3 (1), 39–44. Keshavamurthy, M., Srinath, B.S., Rai, V.R., 2018. Phytochemicals-mediated green synthesis of gold nanoparticles using Pterocarpus santalinus L. (Red Sanders) bark extract and their antimicrobial properties. Part. Sci. Technol. 36 (7), 785–790. Khadivi Derakhshan, F., Dehnad, A., Salouti, M., 2012. Extracellular biosynthesis of gold nanoparticles by metal resistance bacteria: streptomyces griseus. Synth. React. Inorg., Met.-Org., Nano-Met. Chem. 42 (6), 868–871. Khaleel Basha, S., Govindaraju, K., Manikandan, R., Ahn, J.S., Bae, E.Y., Singaravelu, G., 2010. Phytochemical mediated gold nanoparticles and their PTP 1B inhibitory activity. Colloids Surf. B: Biointerfaces 75 (2), 405–409. Kharissova, O.V., Dias, H.V.R., Kharisov, B.I., Pérez, B.O., Pérez, V.M.J., 2013. The greener synthesis of nanoparticles. Trends Biotechnol. 31, 240. Kirupagaran, R., Saritha, A., Bhuvaneswari, S., 2016. Green synthesis of selenium nanoparticles from leaf and stem extract of Leucas lavandulifolia Sm. and their application. J. Nanosci. Technol. 2 (5), 224–226. Koduru, M., Dillip, D.G.R., Narasimha, G., Nannepaga, J.S., Borelli, P.D.P.R., 2012. Phytofabrication and characterization of silver nanoparticles from Piper betle broth. Res. J. Nanosci. Nanotechnol. 2, 17–23. Koduru, M., Nannepaga, J.S., Subba Reddy, B.V., Reddy, C., Narasimha, G., 2013. Palladium nanoparticles: s­ ingle-step plant-mediated green chemical procedure using Piper betle leaves broth and their anti-fungal studies. Int. J. Chem. Anal. Sci. 4, 14–18. Kora, A.J., Arunachalam, J., 2012. Green fabrication of silver nanoparticles by gum tragacanth (Astragalus gummifer): a dual functional reductant and stabilizer. J. Nanomater. 2012, 8. Kora, A.J., Sashidhar, R.B., Arunachalam, J., 2010. Gum kondagogu (Cochlospermum gossypium): a template for the green synthesis and stabilization of silver nanoparticles with antibacterial application. Carbohydr. Polym. 82 (3), 670–679. Kora, A.J., Beedu, S.R., Jayaraman, A., 2012. Size-controlled green synthesis of silver nanoparticles mediated by gum ghatti (Anogeissus latifolia) and its biological activity. Org. Med. Chem. Lett. 2 (1), 17. Kouvaris, P., Delimitis, A., Zaspalis, V., Papadopoulos, D., Tsipas, S.A., Michailidis, N., 2012. Green synthesis and characterization of silver nanoparticles produced using Arbutus Unedo leaf extract. Mater. Lett. 76, 18–20. Krishnaraj, C., Jagan, E.G., Rajasekar, S., Selvakumar, P., Kalaichelvan, P.T., Mohan, N., 2010. Synthesis of silver nanoparticles using Acalypha indica leaf extracts and its antibacterial activity against water borne pathogens. Colloids Surf. B: Biointerfaces 76 (1), 50–56. Krishnaraj, C., Muthukumaran, P., Ramachandran, R., Balakumaran, M.D., Kalaichelvan, P.T., 2014. Acalypha indica Linn: biogenic synthesis of silver and gold nanoparticles and their cytotoxic effects against MDA-MB-231, human breast cancer cells. Biotechnol. Rep. 4 (Suppl C), 42–49. Krishnaswamy, K., Vali, H., Orsat, V., 2014. Value-adding to grape waste: green synthesis of gold nanoparticles. J. Food Eng. 142 (Suppl C), 210–220. Kulkarni, V., Kulkarni, P., 2013. Green synthesis of copper nanoparticles using Ocimum sanctum leaf extract. Int. J. Chem. Stud. 1 (3), 1–4. Kumar, K.P., Paul, W., Sharma, C.P., 2011. Green synthesis of gold nanoparticles with Zingiber officinale extract: characterization and blood compatibility. Process Biochem. 46 (10), 2007–2013. Kumar, P.R., Vivekanandhan, S., Misra, M., Mohanty, A., Satyanarayana, N., 2012a. Soybean (Glycine max) leaf extract based green synthesis of palladium nanoparticles. J. Biomater. Nanobiotechnol. 3, 14–19. Kumar, R., Roopan, S.M., Prabhakarn, A., Khanna, V.G., Chakroborty, S., 2012b. Agricultural waste Annona squamosa peel extract: biosynthesis of silver nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 90 (Suppl C), 173–176. Kumar, S., Daimary, R.M., Swargiary, M., Brahma, A., Kumar, S., Singh, M., 2013. Biosynthesis of silver nanoparticles using Premna herbacea leaf extract and evaluation of its antimicrobial activity against bacteria causing dysentery. Int. J. Pharm. Bio. Sci. 4 (4), 378–384. Kumar, B., Smita, K., Cumbal, L., Debut, A., 2014. Synthesis of silver nanoparticles using Sacha inchi (Plukenetia volubilis L.) leaf extracts. Saudi J. Bio. Sci. 21, 605–609. Kumar, B., Kumari, S., Cumbal, L., Debut, A., 2015a. Lantana camara berry for the synthesis of silver nanoparticles. Asian Pac. J. Trop. Biomed. 5 (3), 192–195.

110

3.  Phytosynthesis of Nanoscale Materials

Kumar, B., Smita, K., Cumbal, L., Debut, A., Camacho, J., Hernández-Gallegos, E., 2015b. Pomosynthesis and ­biological activity of silver nanoparticles using Passiflora tripartita fruit extracts. Adv. Mater. Lett. 6 (2), 127–132. Kumar, V., Singh, D.K., Mohan, S., Hasan, S.H., 2016a. Photo-induced biosynthesis of silver nanoparticles using aqueous extract of Erigeron bonariensis and its catalytic activity against Acridine orange. J. Photochem. Photobiol. B Biol. 155, 39–50. Kumar, V.A., Nakajima, Y., Uchida, T., Hanajiri, T., Maekawa, T., 2016b. Synthesis of nanoparticles composed of silver and silver chloride for a plasmonic photocatalyst using an extract from needles of Pinus densiflora. Mater. Lett. 176 (Suppl C), 169–172. Kumar, B., Smita, K., Cumbal, L., Debut, A., 2017. Sacha inchi (Plukenetia volubilis L.) shell biomass for synthesis of silver nanocatalyst. J. Saudi Chem. Soc. 21 (Suppl. 1), S293–S298. Kumar, D., Kumar, G., Agrawal, V., 2018. Green synthesis of silver nanoparticles using Holarrhena antidysenterica (L.) Wall.bark extract and their larvicidal activity against dengue and filariasis vectors. Parasitol. Res. 117 (2), 377–389. Kumar, M., Mehta, A., Mishra, A., Singh, J., Rawat, M., Basu, S., 2018. Biosynthesis of tin oxide nanoparticles using Psidium guajava leave extract for photocatalytic dye degradation under sunlight. Mater. Lett. 215, 121–124. Kuppusamy, P., Yusoff, M.M., Maniam, G.P., Govindan, N., 2016. Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications—an updated report. Saudi Pharm. J. 24 (4), 473–484. Laokula, P., Klinkaewnaronga, J., Phokha, S., Seraphin, S., 2008. Indium oxide (In2O3) nanoparticles using Aloe vera plant extract: synthesis and optical properties. 2, 161–165. Lee, H.-J., Song, J.Y., Kim, B.S., 2013. Biological synthesis of copper nanoparticles using Magnolia kobus leaf extract and their antibacterial activity. J. Chem. Technol. Biotechnol. 88 (11), 1971–1977. Li, L., Zhang, Z., 2016. Biosynthesis of gold nanoparticles using green alga Pithophora oedogonia with their electrochemical performance for determining carbendazim in soil. Int. J. Electrochem. Sci. 11, 4550–4559. Li, S., Shen, Y., Xie, A., Yu, X., Qiu, L., Zhang, L., Zhang, Q., 2007. Green synthesis of silver nanoparticles using Capsicum annuum L. extract. Green Chem. 9, 852–858. Lin, L., Wang, W., Huang, J., Li, Q., Sun, D., Yang, X., Wang, H., He, N., Wang, Y., 2010. Nature factory of silver nanowires: plant-mediated synthesis using broth of Cassia fistula leaf. Chem. Eng. J. 162 (2), 852–858. Linga Rao, M., Savithramma, N., 2012. Biological synthesis of silver nanoparticles using Svensonia hyderabadensis leaf extract and evaluation of their antimicrobial efficacy. J. Pharm. Sci. Res. 3, 1117–1121. Liny, P., Divya, T.K., Malakar, B., Basavegowda, N., Krishnamurthy, N.B., Dinesh, R., 2012. Preparation of gold nanoparticles from Helianthus annuus (sunflower) flowers and evaluation of their antimicrobialactivities. Int. J. Pharm. Bio. Sci. 3, 439–446. Liu, Q., Liu, H., Yuan, Z., Wei, D., Ye, Y., 2012. Evaluation of antioxidant activity of chrysanthemum extracts and tea beverages by gold nanoparticles-based assay. Colloids Surf. B: Biointerfaces 92, 348–352. Luis López-Miranda, J., Borjas-Garcia, S.E., Esparza, R., Rosas, G., 2016. Synthesis and catalytic evaluation of silver nanoparticles synthesized with Aloysia triphylla leaf extract. J. Clust. Sci. 27 (6), 1989–1999. Lukman, A.I., Gong, B., Marjo, C.E., Roessner, U., Harris, A.T., 2011. Facile synthesis, stabilization, and anti-bacterial performance of discrete Ag nanoparticles using Medicago sativa seed exudates. J. Colloid Interface Sci. 353 (2), 433–444. Madan, H.R., Sharma, S.C., Udayabhanu, D.S., Vidya, Y.S., Nagabhushana, H., Rajanaik, H., Anantharaju, K.S., Prashantha, S.C., Sadananda Maiya, P., 2016. Facile green fabrication of nanostructure ZnO plates, bullets, flower, prismatic tip, closed pine cone: their antibacterial, antioxidant, photoluminescent and photocatalytic properties. Spectrochim. Acta A Mol. Biomol. Spectrosc. 152 (Suppl C), 404–416. Mahdavi, M., Namvar, F., Ahmad, M., Mohamad, R., 2013. Green biosynthesis and characterization of magnetic iron oxide (Fe3O4) nanoparticles using seaweed (Sargassum muticum) aqueous extract. Molecules 18 (5), 5954. Maheswari, R.U., Lakshmi Prabha, A., Nandagopalan, V., Anburaja, V., 2012. Green synthesis of silver nanoparticles by using rhizome extract of Dioscorea oppositifolia L. and their anti microbial activity against human pathogens. Int. J. Pharm. Bio. Sci. 1 (2), 38–42. Maiti, S., Krishnan, D., Barman, G., Ghosh, S.K., Laha, J.K., 2014. Antimicrobial activities of silver nanoparticles synthesized from Lycopersicon esculentum extract. J. Anal. Sci. Technol. 5 (1), 40. Majeed, S., Khanday, M., 2016. Green synthesis of silver nanoparticles using bark extract of Salix alba and its antimicrobial effect against bacteria isolated from dental plaque. Orient. J. Chem. 32 (3), 1611–1618. Majumdar, R., Bag, B.G., Ghosh, P., 2016. Mimusops elengi bark extract mediated green synthesis of gold nanoparticles and study of its catalytic activity. Appl. Nanosci. 6 (4), 521–528.

REFERENCES 111

Makarov, V.V., Love, A.J., Sinitsyna, O.V., Makarova, S.S., Yaminsky, I.V., Taliansky, M.E., Kalinina, N.O., 2014. “Green” nanotechnologies: synthesis of metal nanoparticles using plants. Acta Nat. 6 (1), 35–44. Mallikarjun, K., Narsimha, G., Dillip, G., Praveen, B., Shreedhar, B., Lakshmi, S., 2011. Green synthesis of silver nanoparticles using Ocimum leaf extract and their characterization. Dig. J. Nanomater. Biostruct. 6 (1), 181–186. Mandal, S., Selvakannan, P.R., Phadtare, S., Pasricha, R., Sastry, M., 2002. Synthesis of a stable gold hydrosol by the reduction of chloroaurate ions by the amino acid, aspartic acid. J. Chem. Sci. 114 (5), 513–520. Mane Gavade, S.J., Nikam, G.H., Sabale, S.R., Tamhankar, B.V., 2016. Green synthesis of fluorescent silver nanoparticles using Acacia nilotica gum extract for kinetic studies of 4-nitrophenol reduction. Mater Today Proc. 3 (10, Part B), 4109–4114. Manikandan, R., Manikandan, B., Raman, T., Arunagirinathan, K., Prabhu, N.M., Jothi Basu, M., Perumal, M., Palanisamy, S., Munusamy, A., 2015. Biosynthesis of silver nanoparticles using ethanolic petals extract of Rosa indica and characterization of its antibacterial, anticancer and anti-inflammatory activities. Spectrochim. Acta A Mol. Biomol. Spectrosc. 138 (Suppl C), 120–129. Manjari, G., Saran, S., Arun, T., Vijaya Bhaskara Rao, A., Devipriya, S.P., 2017. Catalytic and recyclability properties of phytogenic copper oxide nanoparticles derived from Aglaia elaeagnoidea flower extract. J. Saudi Chem. Soc. 21 (5), 610–618. Masurkar, S.A., Chaudhari, P.R., Shidore, V.B., Kamble, S.P., 2011. Rapid biosynthesis of silver nanoparticles using Cymbopogan citratus (lemongrass) and its antimicrobial activity. Nanomicro Lett 3, 189. Mata, Y.N., Blázquez, M.L., Ballester, A., González, F., Muñoz, J.A., 2008. Characterization of the biosorption of cadmium, lead and copper with the brown alga Fucus vesiculosus. J. Hazard. Mater. 158 (2), 316–323. Mata, Y.N., Torres, E., Blázquez, M.L., Ballester, A., González, F., Muñoz, J.A., 2009. Gold(III) biosorption and bioreduction with the brown alga Fucus vesiculosus. J. Hazard. Mater. 166 (2), 612–618. Mata, R., Nakkala, J.R., Sadras, S.R., 2016. Polyphenol stabilized colloidal gold nanoparticles from Abutilon indicum leaf extract induce apoptosis in HT-29 colon cancer cells. Colloids Surf. B: Biointerfaces 143, 499–510. Matinise, N., Fuku, X.G., Kaviyarasu, K., Mayedwa, N., Maaza, M., 2017. ZnO nanoparticles via Moringa oleifera green synthesis: physical properties & mechanism of formation. Appl. Surf. Sci. 406 (Suppl C), 339–347. Menon, S., Rajeshkumar, S., Venkat Kumar, S., 2017. A review on biogenic synthesis of gold nanoparticles, characterization, and its applications. Res. Effic. Technol. 3 (4), 516–527. Mishra, P.M., Sahoo, S.K., Naik, G.K., Parida, N., 2015. Biomimetic synthesis, characterization and mechanism of formation of stable silver nanoparticles using Averrhoa carambola L. leaf extract. Mater. Lett. 160, 566–571. Mittal, A.K., Kaler, A., Banerjee, U.C., 2012. Free radical scavenging and antioxidant activity of silver nanoparticles synthesized from flower extract of rhododendron dauricum. Nano Biomed. Eng. 4 (3), 118–124. Mittal, A.K., Bhaumik, J., Kumar, S., Banerjee, U.C., 2014. Biosynthesis of silver nanoparticles: elucidation of prospective mechanism and therapeutic potential. J. Colloid Interface Sci. 415 (Suppl C), 39–47. Mittal, A.K., Tripathy, D., Choudhary, A., Aili, P.K., Chatterjee, A., Singh, I.P., Banerjee, U.C., 2015. Bio-synthesis of silver nanoparticles using Potentilla fulgens Wall. ex Hook. and its therapeutic evaluation as anticancer and antimicrobial agent. Mater. Sci. Eng. C Mater. Biol. Appl. 53, 120–127. Mo, Y., Tang, Y., Wang, S., Lin, J.M., Zhang, H., Luo, D., 2015. Green synthesis of silver nanoparticles using eucalyptus leaf extract. Mater. Lett. 144, 165–167. Moghtader, F., Salouti, M., Türk, M., Pişkin, E., 2014. Nanoemulsions and nonwoven fabrics carrying AgNPs: antibacterial but may be cytotoxic. Artif. Cells Nanomed. Biotechnol. 42 (6), 392–399. Mohammadlou, M., Maghsoudi, H., Jafarizadeh-Malmiri, H., 2016. A review on green silver nanoparticles based on plants: synthesis, potential applications and eco-friendly approach. Int. Food Res. J. 23 (2), 446–463. Mohammed Fayaz, A., Girilal, M., Venkatesan, R., Kalaichelvan, P.T., 2011. Biosynthesis of anisotropic gold nanoparticles using Maduca longifolia extract and their potential in infrared absorption. Colloids Surf. B: Biointerfaces 88 (1), 287–291. Mohan Kumar, K., Mandal, B.K., Kiran Kumar, H.A., Maddinedi, S.B., 2013a. Green synthesis of size controllable gold nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 116, 539–545. Mohan Kumar, K., Mandal, B.K., Siva Kumar, K., Sreedhara Reddy, P., Sreedhar, B., 2013b. Biobased green method to synthesise palladium and iron nanoparticles using Terminalia chebula aqueous extract. Spectrochim. Acta A Mol. Biomol. Spectrosc. 102, 128–133. Moldovan, B., David, L., Achim, M., Clichici, S., Filip, G.A., 2016. A green approach to phytomediated synthesis of silver nanoparticles using Sambucus nigra L. fruits extract and their antioxidant activity. J. Mol. Liq. 221 (Suppl C), 271–278.

112

3.  Phytosynthesis of Nanoscale Materials

Moorthy, S.K., Ashok, C.H., Rao, K.V., Viswanathan, C., 2015. Synthesis and characterization of Mgo nanoparticles by neem leaves through green method. Mater Today Proc. 2 (9, Part A), 4360–4368. Moulton, M.C., Braydich-Stolle, L.K., Nadagouda, M.N., Kunzelman, S., Hussain, S.M., Varma, R.S., 2010. Synthesis, characterization and biocompatibility of “green” synthesized silver nanoparticles using tea polyphenols. Nanoscale 2 (5), 763–770. Moyo, M., Gomba, M., Nharingo, T., 2015. Afzelia quanzensis bark extract for green synthesis of silver nanoparticles and study of their antibacterial activity. Int. J. Ind. Chem. 6 (4), 329–338. Mude, N., Ingle, A., Gade, A., Rai, M., 2009. Synthesis of silver nanoparticles using callus extract of Carica papaya—a first report. J. Plant. Biochem. Biotechnol. 18 (1), 83–86. Mubarak Ali, D., Thajuddin, N., Jeganathan, K., Gunasekaran, M., 2011. Plant extract mediated synthesis of silver and gold nanoparticles and its antibacterial activity against clinically isolated pathogens. Colloids Surf. B: Biointerfaces 85 (2), 360–365. Muchanyereyi, N., Muchenje, T., Nyoni, S., Shumba, M., Mupa, M., Gwatidzo, L., Rahman, D.A., 2017. Green synthesis of silver nanoparticles using euphorbia confinalis stem extract, characterization and evaluation of antimicrobial activity. J. Nanomater. Mol. Nanotechnol. 06, 3. Mukherjee, S., Vinothkumar, B., Prashanthi, S., Bangal, P.R., Sreedhar, B., Patra, C.R., 2013. Potential therapeutic and diagnostic applications of one-step in situ biosynthesized gold nanoconjugates (2-in-1 system) in cancer treatment. RSC Adv. 3 (7), 2318–2329. Mukherjee, S., Chowdhury, D., Kotcherlakota, R., Patra, S., Vinothkumar, B., Bhadra, M.P., Sreedhar, B., Patra, C.R., 2014. Potential theranostics application of bio-synthesized silver nanoparticles (4-in-1 system). Theranostics 4 (3), 316–335. Munnaluri, G., Nivedita, S., Neelam, M.G., Kasilingam, B., Kavitha, T., 2015. Synthesis of silver nanoparticles using cinnamomum zeylanicum bark extract and its antioxidant activity. Nanosci. Nanotechnol. 5 (1), 2–7. Murugan, K., Benelli, G., Panneerselvam, C., Subramaniam, J., Jeyalalitha, T., Dinesh, D., Nicoletti, M., Hwang, J.-S., Suresh, U., Madhiyazhagan, P., 2015a. Cymbopogon citratus-synthesized gold nanoparticles boost the predation efficiency of copepod Mesocyclops aspericornis against malaria and dengue mosquitoes. Exp. Parasitol. 153 (Suppl C), 129–138. Murugan, K., Dinesh, D., Kumar, P.J., 2015b. Datura metal-synthesized silver nanoparticles magnify predation of dragonfly nymphs against the malaria vector Anopheles stephensi. Parasitol. Res. 114 (12), 4645–4654. Muthu, K., Priya, S., 2017. Green synthesis, characterization and catalytic activity of silver nanoparticles using Cassia auriculata flower extract separated fraction. Spectrochim. Acta A Mol. Biomol. Spectrosc. 179 (Suppl C), 66–72. Muthuvel, A., Adavallan, K., Balamurugan, K., Krishnakumar, N., 2014. Biosynthesis of gold nanoparticles using Solanum nigrum leaf extract and screening their free radical scavenging and antibacterial properties. Biomed. Prev. Nutr. 4 (2), 325–332. Nabikhan, A., Kandasamy, K., Raj, A., Alikunhi, N.M., 2010. Synthesis of antimicrobial silver nanoparticles by callus and leaf extracts from saltmarsh plant, Sesuvium portulacastrum L. Colloids Surf. B: Biointerfaces 79 (2), 488–493. Nadeem, M., Abbasi, B.H., Younas, M., Ahmad, W., Khan, T., 2017. A review of the green syntheses and anti-­microbial applications of gold nanoparticles. Green Chem. Lett. Rev. 10 (4), 216–227. Nagajyothi, P.C., Tvm, S., Duk Lee, K., 2012. AgNPs: green synthesis, characterization, antimicrobial, and cytotoxicity studies of methanol and aqueous extracts of pseudocydonia sinensis (Chinese quince) fruit. Synth. React. Inorg., Met.-Org., Nano-Met. Chem. 42, 1339–1344. Nagajyothi, P.C., Sreekanth, T.V.M., Tettey, C.O., Jun, Y.I., Mook, S.H., 2014. Characterization, antibacterial, antioxidant, and cytotoxic activities of ZnO nanoparticles using Coptidis rhizoma. Bioorg. Med. Chem. Lett. 24 (17), 4298–4303. Nagajyothi, P.C., Muthuraman, P., Sreekanth, T.V.M., Kim, D.H., Shim, J., 2017. Green synthesis: in-vitro anticancer activity of copper oxide nanoparticles against human cervical carcinoma cells. Arab. J. Chem. 10 (2), 215–225. Nagajyothi, P.C., Pandurangan, M., Veerappan, M., Kim, D.H., Sreekanth, T.V.M., Shim, J., 2018. Green synthesis, characterization and anticancer activity of yttrium oxide nanoparticles. Mater. Lett. 216, 58–62. Nagaraj, B., Malakar, B., Divya, T.K., Krishnamurthy, N.B., Liny, P., Dinesh, R., 2013. Environmental benign synthesis of gold nanoparticles from the flower extracts of Plumeria alba Linn. (Frangipani) and evaluation of their biological activities. Int. J. Nanomater. Biostruct. 3 (1), 21–25. Nagarajan, S., Arumugam Kuppusamy, K., 2013. Extracellular synthesis of zinc oxide nanoparticle using seaweeds of gulf of Mannar, India. J. Nanobiotechnol. 11 (1), 39. Naheed, A., Seema, S., Radheshyam, R., 2012. Rapid green synthesis of silver and gold nanoparticles using peels of Punica granatum. Adv. Mater. Lett. 3 (5), 376–380.

REFERENCES 113

Naika, H.R., Lingaraju, K., Manjunath, K., Kumar, D., Nagaraju, G., Suresh, D., Nagabhushana, H., 2015. Green synthesis of CuO nanoparticles using Gloriosa superba L. extract and their antibacterial activity. J. Taibah Univ. Sci. 9 (1), 7–12. Nakkala, J.R., Mata, R., Gupta, A.K., Sadras, S.R., 2014. Biological activities of green silver nanoparticles synthesized with Acorous calamus rhizome extract. Eur. J. Med. Chem. 85 (Suppl C), 784–794. Naraginti, S., Kumari, P.L., Das, R.K., Sivakumar, A., Patil, S.H., Andhalkar, V.V., 2016. Amelioration of excision wounds by topical application of green synthesized, formulated silver and gold nanoparticles in albino Wistar rats. Mater. Sci. Eng. C 62, 293–300. Narayanan, K.B., Park, H.H., 2014. Antifungal activity of silver nanoparticles synthesized using turnip leaf extract (Brassica rapa L.) against wood rotting pathogens. Eur. J. Plant Pathol. 140 (2), 185–192. Narayanan, K.B., Sakthivel, N., 2008. Coriander leaf mediated biosynthesis of gold nanoparticles. Mater. Lett. 62, 4588. Narayanan, K.B., Sakthivel, N., 2010. Phytosynthesis of gold nanoparticles using leaf extract of Coleus amboinicus Lour. Mater. Charact. 61 (11), 1232–1238. Naseem, T., Farrukh, M.A., 2015. Antibacterial activity of green synthesis of iron nanoparticles using Lawsonia inermis and Gardenia jasminoides leaves extract. J. Chem. 2015, 7. Nasrollahzadeh, M., Mohammad Sajadi, S., 2015. Green synthesis of copper nanoparticles using Ginkgo biloba L. leaf extract and their catalytic activity for the Huisgen [3+2] cycloaddition of azides and alkynes at room temperature. J. Colloid Interface Sci. 457 (Suppl C), 141–147. Nasrollahzadeh, M., Sajadi, S.M., 2015. Synthesis and characterization of titanium dioxide nanoparticles using Euphorbia heteradena Jaub root extract and evaluation of their stability. Ceram. Int. 41 (10, Part B), 14435–14439. Nasrollahzadeh, M., Mohammad Sajadi, S., Rostami-Vartooni, A., 2015. Green synthesis of CuO nanoparticles by aqueous extract of Anthemis nobilis flowers and their catalytic activity for the A3 coupling reaction. J. Colloid Interface Sci. 459 (Suppl C), 183–188. Nava, O.J., Luque, P.A., Gómez-Gutiérrez, C.M., Vilchis-Nestor, A.R., Castro-Beltrán, A., Mota-González, M.L., Olivas, A., 2017. Influence of Camellia sinensis extract on zinc oxide nanoparticle green synthesis. J. Mol. Struct. 1134 (Suppl C), 121–125. Nazar, N., Bibi, I., Kamal, S., Iqbal, M., Nouren, S., Jilani, K., Umair, M., Ata, S., 2018. Cu nanoparticles synthesis using biological molecule of P. granatum seeds extract as reducing and capping agent: growth mechanism and photo-catalytic activity. Int. J. Biol. Macromol. 106, 1203–1210. Ndikau, M., Noah, N.M., Andala, D.M., Masika, E., 2017. Green synthesis and characterization of silver nanoparticles using Citrullus lanatus fruit rind extract. Int. J. Anal. Chem. 2017, 9. Nezamdoost, T., Bagherieh-Najjar, M.B., Aghdasi, M., 2014. Biogenic synthesis of stable bioactive silver chloride nanoparticles using Onosma dichroantha Boiss. root extract. Mater. Lett. 137 (Suppl C), 225–228. Noruzi, M., 2015. Biosynthesis of gold nanoparticles using plant extracts. Bioprocess Biosyst. Eng. 38 (1), 1–14. Ochieng, P.E., Iwuoha, E., Michira, I., Masikini, M., Ondiek, J., Githira, P., 2015. Green route synthesis and characterization of ZnO nanoparticles using Spathodea campanulata. Int. J. Biochem. Phys 23, 53–61. Okafor, F., Janen, A., Kukhtareva, T., Edwards, V., Curley, M., 2013. Green synthesis of silver nanoparticles, their characterization, application and antibacterial activity. Int. J. Environ. Res. Public Health 10 (10), 5221. Olajire, A.A., Adeyeye, G.O., Yusuf, R.A., 2017. Alchornea laxiflora bark extract assisted green synthesis of platinum nanoparticles for oxidative desulphurization of model oil. J. Clust. Sci. 28 (3), 1565–1578. Padalia, H., Moteriya, P., Chanda, S., 2015. Green synthesis of silver nanoparticles from marigold flower and its synergistic antimicrobial potential. Arab. J. Chem. 8 (5), 732–741. Padalia, H., Moteriya, P., Khara, G., Chanda, S., 2017. Green synthesis, characterization, antimicrobial and cytotoxic activities of zinc oxide nanoparticles from Cinnamomum verum bark extract. OpenNano. https://doi. org/10.1016/j.onano.2017.06.001. Padil, V.V.T., Černík, M., 2013. Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application. Int. J. Nanomedicine 8, 889–898. Parameshwaran, R., Kalaiselvam, S., Jayavel, R., 2013. Green synthesis of silver nanoparticles using Beta vulgaris: role of process conditions on size distribution and surface structure. Mater. Chem. Phys. 140 (1), 135–147. Parthibana, C., Sundaramurthy, N., 2015. Biosynthesis, characterization of ZnO nanoparticles by using pyrus pyrifolia leaf extract and their photocatalytic activity. Int. Res. J. Eng. Technol. 4 (10), 9710–9718. Patil, R.S., Kokate, M.R., Kolekar, S.S., 2012. Bioinspired synthesis of highly stabilized silver nanoparticles using Ocimum tenuiflorum leaf extract and their antibacterial activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 91, 234–238.

114

3.  Phytosynthesis of Nanoscale Materials

Patra, S., Mukherjee, S., Barui, A.K., Ganguly, A., Sreedhar, B., Patra, C.R., 2015. Green synthesis, characterization of gold and silver nanoparticles and their potential application for cancer therapeutics. Mater. Sci. Eng. C 53 (Suppl C), 298–309. Pattanayak, S., Mollick, M.M.R., Maity, D., Chakraborty, S., Dash, S.K., Chattopadhyay, S., Roy, S., Chattopadhyay, D., Chakraborty, M., 2017. Butea monosperma bark extract mediated green synthesis of silver nanoparticles: characterization and biomedical applications. J. Saudi Chem. Soc. 21 (6), 673–684. Paulkumar, K., Gnanajobitha, G., Vanaja, M., Rajeshkumar, S., Malarkodi, C., Pandian, K., Annadurai, G., 2014. Piper nigrum leaf and stem assisted green synthesis of silver nanoparticles and evaluation of its antibacterial activity against agricultural plant pathogens. Sci. World J. 2014, 9. Pavani, K.V., K, G., Banerjee, A., Suresh, S., 2013. Phyto-synthesis of silver nanoparticles using extracts of Ipomoea indica flowers. Am. J. Nanomat. 1 (1), 5–8. Pethakamsetty, L., Kothapenta, K., Nammi, H.R., Ruddaraju, L.K., Kollu, P., Yoon, S.G., Pammi, S.V.N., 2017. Green synthesis, characterization and antimicrobial activity of silver nanoparticles using methanolic root extracts of Diospyros sylvatica. J. Environ. Sci. 55 (Suppl C), 157–163. Petla, R.K., Vivekanandhan, S., Misra, M., Mohanty, A.K., Satyanarayana, N., 2012. Soybean (Glycine max) leaf extract based green synthesis of palladium nanoparticles. J Biomater Nanobiotechnol 03 (01), 6. Philip, D., 2010. Green synthesis of gold and silver nanoparticles using Hibiscus rosa sinensis. Physica E 42 (5), 1417–1424. Philip, D., Unni, C., 2011. Extracellular biosynthesis of gold and silver nanoparticles using Krishna tulsi (Ocimum sanctum) leaf. Physica E 43 (7), 1318–1322. Poinern, G.E.J., Chapman, P., Le, X., Fawcett, D., 2013a. Green biosynthesis of gold nanometre scale plates using the leaf extracts from an indigenous Australian plant Eucalyptus macrocarpa. Gold Bull. 46 (3), 165–173. Poinern, G.E.J., Shah, M., Chapman, P., Fawcett, D., 2013b. Green biosynthesis of silver nanocubes using the leaf extracts from extracts from Eucalyptus macrocarpa. Nano Bull. 2 (1), 1–7. Poopathi, S., De Britto, L.J., Praba, V.L., Mani, C., Praveen, M., 2015. Synthesis of silver nanoparticles from Azadirachta indica—a most effective method for mosquito control. Environ. Sci. Pollut. Res. 22 (4), 2956–2963. Pourmortazavi, S.M., Taghdiri, M., Makari, V., Rahimi-Nasrabadi, M., 2015. Procedure optimization for green synthesis of silver nanoparticles by aqueous extract of Eucalyptus oleosa. Spectrochim. Acta A Mol. Biomol. Spectrosc. 136, 1249–1254. Ppn, V.K., Shameem, U., Kollu, P., Kalyani, R.L., Pammi, S.V.N., 2015. Green synthesis of copper oxide nanoparticles using aloe vera leaf extract and its antibacterial activity against fish bacterial pathogens. Bionanoscience 5, 135–139. Prasad, R., 2014. Synthesis of silver nanoparticles in photosynthetic plants. J. Nanopart. 2014, 8. Prasad, T., Elumalai, E.K., 2011. Biofabrication of Ag nanoparticles using Moringa oleifera leaf extract and their antimicrobial activity. Asian Pac. J. Trop. Biomed. 1 (6), 439–442. Prasad, K.S., Patra, A., Shruthi, G., Chandan, S., 2017. Aqueous extract of Saraca indica leaves in the synthesis of copper oxide nanoparticles: finding a way towards going green. J. Nanotechnol. 2017, 6. Prathap, M., Alagesan, A., Ranjitha Kumari, B.D., 2014. Anti-bacterial activities of silver nanoparticles synthesized from plant leaf extract of Abutilon indicum (L.) sweet. J Nanostructure Chem 4, 106. Prathna, T.C., Chandrasekaran, N., Raichur, A.M., Mukherjee, A., 2011. Kinetic evolution studies of silver nanoparticles in a bio-based green synthesis process. Colloids Surf. A Physicochem. Eng. Asp. 377 (1–3), 212–216. Qian, Y., Yao, J., Russel, M., Chen, K., Wang, X., 2015. Characterization of green synthesized nano-formulation (ZnO–A. vera) and their antibacterial activity against pathogens. Environ. Toxicol. Pharmacol. 39 (2), 736–746. Raghunandan, D., Bedre, M.D., Basavaraja, S., Sawle, B., Manjunath, S.Y., Venkataraman, A., 2010. Rapid biosynthesis of irregular shaped gold nanoparticles from macerated aqueous extracellular dried clove buds (Syzygium aromaticum) solution. Colloids Surf. B: Biointerfaces 79 (1), 235–240. Rai, A., Singh, A., Ahmad, A., Sastry, M., 2006. Role of halide ions and temperature on the morphology of biologically synthesized gold nanotriangles. Langmuir 22, 736–741. Rai, A., Chaudhary, M., Ahmad, A., Bhargava, U., Sastry, M., 2007. Synthesis of triangular Au core-Ag shell nanoparticles. Mater. Res. Bull. 42, 1212. Rai, M., Yadav, A., Gade, A., 2008. Current trends in phytosynthesis of metal nanoparticles. Crit. Rev. Biotechnol. 28, 277–284. Rajakumar, G., Abdul Rahuman, A., 2011. Larvicidal activity of synthesized silver nanoparticles using Eclipta prostrata leaf extract against filariasis and malaria vectors. Acta Trop. 118 (3), 196–203.

REFERENCES 115

Rajakumar, G., Rahuman, A.A., Chung, I.-M., Kirthi, A.V., Marimuthu, S., Anbarasan, K., 2015. Antiplasmodial activity of eco-friendly synthesized palladium nanoparticles using Eclipta prostrata extract against Plasmodium berghei in Swiss albino mice. Parasitol. Res. 114 (4), 1397–1406. Rajendran, S.P., Sengodan, K., 2017. Synthesis and characterization of zinc oxide and iron oxide nanoparticles using Sesbania grandiflora leaf extract as reducing agent. J. Nanosci. 2017, 7. Rajeshkumar, S., 2016. Synthesis of silver nanoparticles using fresh bark of Pongamia pinnata and characterization of its antibacterial activity against gram positive and gram negative pathogens. Res. Effic. Technol. 2 (1), 30–35. Rajeshkumar, S., Bharath, L.V., 2017. Mechanism of plant-mediated synthesis of silver nanoparticles–a review on biomolecules involved, characterisation and antibacterial activity. Chem. Biol. Interact. 273 (Suppl C), 219–227. Rajiv, P., Rajeshwari, S., Venckatesh, R., 2013. Bio-fabrication of zinc oxide nanoparticles using leaf extract of Parthenium hysterophorus L. and its size-dependent antifungal activity against plant fungal pathogens. Spectrochim. Acta A Mol. Biomol. Spectrosc. 112 (Suppl C), 384–387. Rajkuberan, C., Prabukumar, S., Sathishkumar, G., Wilson, A., Ravindran, K., Sivaramakrishnan, S., 2017. Facile synthesis of silver nanoparticles using Euphorbia antiquorum L. latex extract and evaluation of their biomedical perspectives as anticancer agents. J. Saudi Chem. Soc. 21 (8), 911–919. Raju, D., Vishwakarma, R.K., Khan, B.M., Mehta, U.J., Ahmad, A., 2014. Biological synthesis of cationic gold nanoparticles and binding of plasmid DNA. Mater. Lett. 129 (Suppl C), 159–161. Ramar, M., Manikandan, B., Marimuthu, P.N., Raman, T., 2015. Synthesis of silver nanoparticles using Solanum trilobatum fruits extract and its antibacterial, cytotoxic activity against human breast cancer cell line MCF 7. Spectrochim. Acta A Mol. Biomol. Spectrosc. 140, 223–228. Ramesh, C., Hariprasad, M., Ragunathan, V., 2011. Effect of Arachis hypogaea L. leaf extract on barfoed’s solution; green synthesis of Cu2O nanoparticles and its antibacterial effect. 7, 995–999. Ramesh, M., Anbuvannan, M., Viruthagiri, G., 2015. Green synthesis of ZnO nanoparticles using Solanum nigrum leaf extract and their antibacterial activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 136 (Part B), 864–870. Ramkumar, V.S., Pugazhendhi, A., Gopalakrishnan, K., Sivagurunathan, P., Saratale, G.D., Dung, T.N.B., Kannapiran, E., 2017. Biofabrication and characterization of silver nanoparticles using aqueous extract of seaweed Enteromorpha compressa and its biomedical properties. Biotechnol. Rep. 14, 1–7. Ramteke, C., Chakrabarti, T., Sarangi, B.K., Pandey, R.-A., 2013. Synthesis of silver nanoparticles from the aqueous extract of leaves of Ocimum sanctum for enhanced antibacterial activity. J. Chem. 2013, 7. Rao, M.D., Gautam, P., 2016. Synthesis and characterization of ZnO nanoflowers using Chlamydomonas reinhardtii: a green approach. Environ. Prog. Sustain. Energy 35 (4), 1020–1026. Rao, N.H., N, L., Pammi, S.V.N., Kollu, P., S, G., P, L., 2016. Green synthesis of silver nanoparticles using methanolic root extracts of Diospyros paniculata and their antimicrobial activities. Mater. Sci. Eng. C 62 (Suppl C), 553–557. Rathi Sre, P.R., Reka, M., Poovazhagi, R., Arul Kumar, M., Murugesan, K., 2015. Antibacterial and cytotoxic effect of biologically synthesized silver nanoparticles using aqueous root extract of Erythrina indica lam. Spectrochim. Acta A Mol. Biomol. Spectrosc. 135, 1137–1144. Reddy, J., Mata, R., Bhagat, E., Sudha Rani, S., 2015. Green synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract: study of antioxidant and anticancer activities. J. Nanopart. Res. 17 (3), 151–158. Rodríguez-León, E., Iñiguez-Palomares, R., Navarro, R.E., Herrera-Urbina, R., Tánori, J., Iñiguez-Palomares, C., Maldonado, A., 2013. Synthesis of silver nanoparticles using reducing agents obtained from natural sources (Rumex hymenosepalus extracts). Nanoscale Res. Lett. 8 (1), 318. Roni, M., Murugan, K., Panneerselvam, C., Subramaniam, J., Hwang, J.-S., 2013. Evaluation of leaf aqueous extract and synthesized silver nanoparticles using Nerium oleander against Anopheles stephensi (Diptera: Culicidae). Parasitol. Res. 112 (3), 981–990. Roopan, S.M., Bharathi, A., Kumar, R., Khanna, V.G., Prabhakarn, A., 2012a. Acaricidal, insecticidal, and larvicidal efficacy of aqueous extract of Annona squamosa L peel as biomaterial for the reduction of palladium salts into nanoparticles. Colloids Surf. B: Biointerfaces 92, 209–212. Roopan, S.M., Bharathi, A., Prabhakarn, A., Abdul Rahuman, A., Velayutham, K., Rajakumar, G., Padmaja, R.D., Lekshmi, M., Madhumitha, G., 2012b. Efficient phyto-synthesis and structural characterization of rutile TiO2 nanoparticles using Annona squamosa peel extract. Spectrochim. Acta A Mol. Biomol. Spectrosc. 98 (Suppl C), 86–90. Rosarin, S., Arulmozhi, V., Nagarajan, S., Mirunalini, S., 2013. Antiproliferative effect of silver nanoparticles synthesized using amla on Hep2 cell line. Asian Pac. J. Trop. Med. 6, 1–10.

116

3.  Phytosynthesis of Nanoscale Materials

Rout, A., Jena, P.K., Parida, U.K., Bindhani, B.K., 2013. Green synthesis of silver nanoparticles using leaves extract of Centella asiatica L. For studies against human pathogens. Int. J. Pharm. Bio. Sci. 4 (4), 661–674. Roy, S., Das, T.K., 2015. Plant mediated green synthesis of silver nanoparticles–a review. Int. J. Plant Biol. Res. 3 (3), 1044–1059. Rupiasih, N.N., Aher, A., Gosavi, S., Vidyasagar, P.B., 2015. Green synthesis of silver nanoparticles using latex extract of Thevetia peruviana: a novel approach towards poisonous plant utilization. In: Gaol, F.L., Shrivastava, K., Akhtar, J. (Eds.), Recent Trends in Physics of Material Science and Technology. Springer Singapore, Singapore, pp. 1–10. Sadeghi, B., 2015. Zizyphus mauritiana extract-mediated green and rapid synthesis of gold nanoparticles and its antibacterial activity. J Nanostructure Chem 5 (3), 265–273. Sadeghi, B., Gholamhoseinpoor, F., 2015. A study on the stability and green synthesis of silver nanoparticles using Ziziphora tenuior (Zt) extract at room temperature. Spectrochim. Acta A Mol. Biomol. Spectrosc. 134, 310–315. Sadeghi, B., Mohammadzadeh, M., Babakhani, B., 2015a. Green synthesis of gold nanoparticles using Stevia rebaudiana leaf extracts: characterization and their stability. J. Photochem. Photobiol. B Biol. 148 (Suppl C), 101–106. Sadeghi, B., Rostami, A., Momeni, S.S., 2015b. Facile green synthesis of silver nanoparticles using seed aqueous extract of Pistacia atlantica and its antibacterial activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 134, 326–332. Safaepour, M., Shahverdi, A.R., Shahverdi, H.R., Khorramizadeh, M.R., Gohari, A.R., 2009. Green synthesis of small silver nanoparticles using geraniol and its cytotoxicity against Fibrosarcoma-Wehi 164. Avicenna J Med Biotechnol 1 (2), 111–115. Salari, Z., Danafar, F., Dabaghi, S., Ataei, S.A., 2016. Sustainable synthesis of silver nanoparticles using macroalgae Spirogyra varians and analysis of their antibacterial activity. J. Saudi Chem. Soc. 20 (4), 459–464. Salem, W.M., Haridy, M., Sayed, W.F., Hassan, N.H., 2014. Antibacterial activity of silver nanoparticles synthesized from latex and leaf extract of Ficus sycomorus. Ind. Crop. Prod. 62, 228–234. Salouti, M., Faghri Zonooz, N., 2017. Biosynthesis of metal and semiconductor nanoparticles, scale-up, and their applications. In: Ghorbanpour, M., Manika, K., Varma, A. (Eds.), Nanoscience and Plant–Soil Systems. Springer International Publishing, Cham, pp. 21–70. Sangaru, S.S., Rai, A., Ankamwar, B., Singh, A., Ahmad, A., Sastry, M., 2004. Biological synthesis of triangular gold nanoprisms. Nat. Mater. 3, 482–488. Santhoshkumar, T., Rahuman, A., Rajakumar, G., Marimuthu, S., Bagavan, A., Jayaseelan, C., Zahir, A.A., Elango, G., Kamaraj, C., 2011. Synthesis of silver nanoparticles using Nelumbo nucifera leaf extract and its larvicidal activity against malaria and filariasis vectors. Parasitol. Res. 108 (3), 693–702. Santhoshkumar, J., Kumar, S.V., Rajeshkumar, S., 2017. Synthesis of Zinc Oxide Nanoparticles Using Plant Leaf Extract Against Urinary Tract Infection Pathogen. Resource-Efficient Technologies. Saraniya Devi, J., Bhimba, V., 2014. Antimicrobial potential of silver nanoparticles synthesized using Ulva reticulata. Asian J. Pharm. Clin. Res. 7, 82–85. Saranyaadevi, K., Subha, V., Ernest Ravindran, R.S., Renganathan, S., 2014. Synthesis and characterization of copper nanoparticle using capparis zeylanica leaf extract. Int. J. ChemTech Res. 6 (10), 4533–4541. Sathishkumar, M., Sneha, K., Kwak, I.S., Mao, J., Tripathy, S.J., Yun, Y.S., 2009a. Phyto-crystallization of palladium through reduction process using Cinnamom zeylanicum bark extract. J. Hazard. Mater. 171 (1), 400–404. Sathishkumar, M., Sneha, K., Won, S.W., Cho, C.W., Kim, S., Yun, Y.S., 2009b. Cinnamon zeylanicum bark extract and powder mediated green synthesis of nano-crystalline silver particles and its bactericidal activity. Colloids Surf. B: Biointerfaces 73 (2), 332–338. Sathishkumar, M., Sneha, K., Yun, Y.-S., 2010. Immobilization of silver nanoparticles synthesized using Curcuma longa tuber powder and extract on cotton cloth for bactericidal activity. Bioresour. Technol. 101 (20), 7958–7965. Saxena, A., Tripathi, R.M., Zafar, F., Singh, P., 2012. Green synthesis of silver nanoparticles using aqueous solution of Ficus benghalensis leaf extract and characterization of their antibacterial activity. Mater. Lett. 67, 91–94. Scarano, G., Morelli, E., 2003. Properties of phytochelatin-coated CdS nanocrystallites formed in a marine phytoplanktonic alga (Phaeodactylum tricornutum, Bohlin) in response to Cd. Plant Sci. 165 (4), 803–810. Selvam, K., Sudhakar, C., Govarthanan, M., Thiyagarajan, P., Sengottaiyan, A., Senthilkumar, B., Selvankumar, T., 2017. Eco-friendly biosynthesis and characterization of silver nanoparticles using Tinospora cordifolia (Thunb.) Miers and evaluate its antibacterial, antioxidant potential. J. Radiat. Res. Appl. Sci. 10 (1), 6–12.

REFERENCES 117

Senapati, S., Syed, A., Moeez, S., Kumar, A., Ahmad, A., 2012. Intracellular synthesis of gold nanoparticles using alga Tetraselmis kochinensis. Mater. Lett. 79 (Suppl C), 116–118. Shah, W., Patil, U., Sharma, A., 2014. Green synthesis of silver nanoparticles from stem bark extract of Terminalia tomentosa Roxb. (Wight & Arn.). Der. Pharma Chemica 6, 197–202. Shah, M., Fawcett, D., Sharma, S., Tripathy, S., Poinern, G., 2015. Green synthesis of metallic nanoparticles via biological entities. Mater. Des. 8 (11), 5377. Shalaby, T., 2015. Green synthesis of gold nanoparticles using cumin seeds and gum arabic: studying their photothermal efficiency. Nanosci. Nanotechnol. 2015, 89–96. Shankar, S.S., Ahmad, A., Pasricha, R., Sastry, M., 2003a. Bioreduction of chloroaurate ions by geranium leaves and its endophytic fungus yields gold nanoparticles of different shapes. J. Mater. Chem. 13, 1822–1846. Shankar, S.S., Ahmad, A., Sastry, M., 2003b. Geranium leaf assisted biosynthesis of silver nanoparticles. Biotechnol. Prog. 19 (6), 1627–1631. Shankar, S.S., Rai, A., Ahmad, A., Sastry, M., 2004. Rapid synthesis of Au, Ag, and bimetallic Au core–Ag shell nanoparticles using Neem (Azadirachta indica) leaf broth. J. Colloid Interface Sci. 275 (2), 496–502. Shankar, D., Shobana, S., Karuppusamy, I., Pugazhendhi, A., Ramkumar, V.S., Arvindnarayan, S., Kumar, G., 2016. A review on the biosynthesis of metallic nanoparticles (gold and silver) using bio-components of microalgae: formation mechanism and applications. Enzym. Microb. Technol. 95 (Suppl C), 28–44. Sharma, N.C., Sahi, S.V., Nath, S., Parsons, J.G., Gardea-Torresdey, J.L., Pal, T., 2007. Synthesis of plant-mediated gold nanoparticles and catalytic role of biomatrix-embedded nanomaterials. Environ. Sci. Technol. 41 (14), 5137–5142. Sharma, B., Purkayastha, D.D., Hazra, S., Gogoi, L., Bhattacharjee, C.R., Ghosh, N.N., Rout, J., 2014. Biosynthesis of gold nanoparticles using a freshwater green alga, Prasiola crispa. Mater. Lett. 116 (Suppl C), 94–97. Sharma, J.K., Akhtar, M.S., Ameen, S., Srivastava, P., Singh, G., 2015. Green synthesis of CuO nanoparticles with leaf extract of Calotropis gigantea and its dye-sensitized solar cells applications. J. Alloys Compd. 632 (Suppl C), 321–325. Sharma, J.K., Srivastava, P., Ameen, S., Akhtar, M.S., Sengupta, S.K., Singh, G., 2017. Phytoconstituents assisted green synthesis of cerium oxide nanoparticles for thermal decomposition and dye remediation. Mater. Res. Bull. 91 (Suppl C), 98–107. Sharmila, G., Farzana Fathima, M., Haries, S., Geetha, S., Manoj Kumar, N., Muthukumaran, C., 2017. Green synthesis, characterization and antibacterial efficacy of palladium nanoparticles synthesized using Filicium decipiens leaf extract. J. Mol. Struct. 1138 (Suppl C), 35–40. Sheikhloo, Z., Salouti, M., Katiraee, F., 2011. Biological synthesis of gold nanoparticles by fungus Epicoccum nigrum. J. Clust. Sci. 22 (4), 661–665. Shende, S., Ingle, A.P., Gade, A., Rai, M., 2015. Green synthesis of copper nanoparticles by Citrus medica Linn. (Idilimbu) juice and its antimicrobial activity. World J. Microbiol. Biotechnol. 31 (6), 865–873. Sheny, D.S., Mathew, J., Philip, D., 2011. Phytosynthesis of Au, Ag and Au–Ag bimetallic nanoparticles using aqueous extract and dried leaf of Anacardium occidentale. Spectrochim. Acta A Mol. Biomol. Spectrosc. 79 (1), 254–262. Sheny, D.S., Philip, D., Mathew, J., 2012. Rapid green synthesis of palladium nanoparticles using the dried leaf of Anacardium occidentale. Spectrochim. Acta A Mol. Biomol. Spectrosc. 91 (Suppl C), 35–38. Sheny, D.S., Philip, D., Mathew, J., 2013. Synthesis of platinum nanoparticles using dried Anacardium occidentale leaf and its catalytic and thermal applications. Spectrochim. Acta A Mol. Biomol. Spectrosc. 114, 267–271. Shi, L.B., Tang, P.F., Zhang, W., Zhao, Y.P., Zhang, L.C., Zhang, H., 2017. Green synthesis of CuO nanoparticles using Cassia auriculata leaf extract and in vitro evaluation of their biocompatibility with rheumatoid arthritis macrophages (RAW 264.7). Trop. J. Pharm. Res. 16 (1), 185–192. Shikuo, L., Yuhua, S., Anjian, X., Xuerong, Y., Xiuzhen, Z., Liangbao, Y., Chuanhao, L., 2007. Rapid, room-temperature synthesis of amorphous selenium/protein composites using Capsicum annuum L extract. Nanotechnology 18 (40), 405101. Siddiqi, K.S., Husen, A., 2017. Recent advances in plant-mediated engineered gold nanoparticles and their application in biological system. J. Trace Elem. Med. Biol. 40 (Suppl C), 10–23. Singaravelu, G., Arockiamary, J.S., Kumar, V.G., Govindaraju, K., 2007. A novel extracellular synthesis of monodisperse gold nanoparticles using marine alga, Sargassum wightii Greville. Colloids Surf. B: Biointerfaces 57 (1), 97–101. Singh, C., Sharma, V., Naik, P., Khandelwal, V., Singh, H., 2002. A green biogenic approach for synthesis of gold and silver nanoparticles using Zingiber officinale. Dig J Nanomater Biostruct 6, 535–542. Singh, A., Jain, D., Upadhyay, M., Khandelwal, N., Verma, H.N., 2010a. Green synthesis of silver nanoparticles using Argemone mexicana leaf extract and evaluation of their antimicrobial activities. Dig J Nanomater Biostruct 5, 483–489.

118

3.  Phytosynthesis of Nanoscale Materials

Singh, A.K., Talat, M., Singh, D.P., Srivastava, O.N., 2010b. Biosynthesis of gold and silver nanoparticles by natural precursor clove and their functionalization with amine group. J. Nanopart. Res. 12 (5), 1667–1675. Singh, M., Kalaivani, R., Manikandan, S., Sangeetha, N., Kumaraguru, A.K., 2013a. Facile green synthesis of variable metallic gold nanoparticle using Padina gymnospora, a brown marine macroalga. Appl. Nanosci. 3 (2), 145–151. Singh, S., Saikia, J.P., Buragohain, A.K., 2013b. A novel ‘green’ synthesis of colloidal silver nanoparticles (SNP) using Dillenia indica fruit extract. Colloids Surf. B: Biointerfaces 102 (Suppl C), 83–85. Singh, P., Kim, Y.-J., Zhang, D., Yang, D.-C., 2016a. Biological synthesis of nanoparticles from plants and microorganisms. Trends Biotechnol. 34 (7), 588–599. Singh, P., Kim, Y.J., Wang, C., Mathiyalagan, R., El-Agamy Farh, M., Yang, D.C., 2016b. Biogenic silver and gold nanoparticles synthesized using red ginseng root extract, and their applications. Artif. Cells Nanomed. Biotechnol. 44 (3), 811–816. Singh, P., Kim, Y.J., Yang, D.C., 2016c. A strategic approach for rapid synthesis of gold and silver nanoparticles by Panax ginseng leaves. Artif. Cells Nanomed. Biotechnol. 44 (8), 1949–1957. Singh, A.K., Tiwari, R., Kumar, V., Singh, P., Riyazat Khadim, S.K., Tiwari, A., Srivastava, V., Hasan, S.H., Asthana, R.K., 2017. Photo-induced biosynthesis of silver nanoparticles from aqueous extract of Dunaliella salina and their anticancer potential. J. Photochem. Photobiol. B Biol. 166 (Suppl C), 202–211. Singhal, G., Bhavesh, R., Kasariya, K., Sharma, A.R., Singh, R.P., 2011. Biosynthesis of silver nanoparticles using Ocimum sanctum (Tulsi) leaf extract and screening its antimicrobial activity. J. Nanopart. Res. 13, 2981–2988. Siva, K., Sivapunyam, A., Kadarkarai, M., Kalimuthu, K., Marimuthu, R., Ponnan, A., Balamurugan, C., Vellingiri, B., 2016. Bio fabrication of silver nanoparticle from Argemone mexicana for the control of Aedes albopictus and their antimicrobial activity. Curr. Pharm. Biotechnol. 17 (14), 1285–1294. Slater, T.J.A., Lewis, E.A., Haigh, S.J., 2016. Energy dispersive X-ray tomography for 3D elemental mapping of individual nanoparticles. J. Vis. Exp. (113)52815. Song, J.Y., Kim, B.S., 2008. Biological synthesis of bimetallic Au/Ag nanoparticles using persimmon (Diopyros kaki) leaf extract. Korean J. Chem. Eng. 25 (4), 808–811. Song, J.Y., Kim, B.S., 2009. Rapid biological synthesis of silver nanoparticles using plant leaf extracts. Bioprocess Biosyst. Eng. 32, 79–84. Song, J.Y., Jang, H.-K., Kim, B.S., 2009a. Biological synthesis of gold nanoparticles using Magnolia kobus and Diopyros kaki leaf extracts. Process Biochem. 44 (10), 1133–1138. Song, J.Y., Kwon, E.-Y., Kim, B.S., 2009b. Biological synthesis of platinum nanoparticles using Diopyros kaki leaf extract. Bioprocess Biosyst. Eng. 33 (1), 159. Soundarrajan, C., Sankari, A., Dhandapani, P., Maruthamuthu, S., Ravichandran, S., Sozhan, G., Palaniswamy, N., 2012. Rapid biological synthesis of platinum nanoparticles using Ocimum sanctum for water electrolysis applications. Bioprocess Biosyst. Eng. 35 (5), 827–833. Stalin Dhas, T., Ganesh Kumar, V., Stanley Abraham, L., Karthick, V., Govindaraju, K., 2012. Sargassum myriocystum mediated biosynthesis of gold nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 99 (Suppl C), 97–101. Stalin Dhas, T., Ganesh Kumar, V., Karthick, V., Jini Angel, K., Govindaraju, K., 2014. Facile synthesis of silver chloride nanoparticles using marine alga and its antibacterial efficacy. Spectrochim. Acta A Mol. Biomol. Spectrosc. 120 (Suppl C), 416–420. Subramaniyam, V., Subashchandrabose, S., Palanisami, T., Mallavarapu, M., Chen, Z., Naidu, R., 2015. Chlorococcum sp. MM11—a novel phyco-nanofactory for the synthesis of iron nanoparticles. J. Appl. Phycol. 27, 1861–1869. Sudhasree, S., Krishnadoss, V., Mahalakshmi, S., Kurian, G., 2015. Desmodium gangeticum root aqueous extract mediated synthesis of Ni nanoparticle and its biological evaluation. Int. J. Pharm. Pharm. Sci. 7, 141–146. Suganya, A., Murugan, K., Kovendan, K., Mahesh Kumar, P., Hwang, J.-s., 2013a. Green synthesis of silver nanoparticles using Murraya koenigii leaf extract against Anopheles stephensi and Aedes aegypti. Parasitol. Res. 112 (4), 1385–1397. Suganya, A., Murugan, K., Kovendan, K., Mahesh Kumar, P., Hwang, J.S., 2013b. Phytochemical screening and antibacterial activity from nerium oleander and evaluvate their plant mediated nanoparticle synthesis. Parasitol. Res. 112, 1385–1397. Sukirtha, R., Priyanka, K.M., Antony, J.J., Kamalakkannan, S., Thangam, R., Gunasekaran, P., Krishnan, M., Achiraman, S., 2012. Cytotoxic effect of green synthesized silver nanoparticles using Melia azedarach against in vitro HeLa cell lines and lymphoma mice model. Process Biochem. 47 (2), 273–279. Suman, T.Y., Radhika Rajasree, S.R., Kanchana, A., Elizabeth, S.B., 2013. Biosynthesis, characterization and cytotoxic effect of plant mediated silver nanoparticles using Morinda citrifolia root extract. Colloids Surf. B: Biointerfaces 106, 74–78.

REFERENCES 119

Sun, Q., Cai, X., Li, J., Zheng, M., Chen, Z., Yu, C.-P., 2014. Green synthesis of silver nanoparticles using tea leaf extract and evaluation of their stability and antibacterial activity. Colloids Surf. A Physicochem. Eng. Asp. 444, 226–231. Sundaramurthy, N., Parthiban, C., 2015. Biosynthesis of copper oxide nanoparticles using Pyrus pyrifolia leaf extract and evolve the catalytic activity. Int. Res. J. Eng. Technol. 2, 332–337. Sundararajan, B., Ranjitha Kumari, B.D., 2017. Novel synthesis of gold nanoparticles using Artemisia vulgaris L. leaf extract and their efficacy of larvicidal activity against dengue fever vector Aedes aegypti L. J. Trace Elem. Med. Biol. 43, 187–196. Sundrarajan, M., Ambika, S., Bharathi, K., 2015. Plant-extract mediated synthesis of ZnO nanoparticles using Pongamia pinnata and their activity against pathogenic bacteria. Adv. Powder Technol. 26 (5), 1294–1299. Sunita, D., Tambhale, D., Parag, V., Adhyapak, A., 2014. Facile green synthesis of silver nanoparticles using Psoralea corylifolia. Seed extract and their in-vitro antimicrobial activities. Int. J. Pharm. Bio. Sci. 5 (1), 457–467. Supraja, N., Prasad, T.N.V.K.V., Krishna, T.G., David, E., 2016. Synthesis, characterization, and evaluation of the antimicrobial efficacy of Boswellia ovalifoliolata stem bark-extract-mediated zinc oxide nanoparticles. Appl. Nanosci. 6 (4), 581–590. Suranjit Prasad Darshit Pathak, K., Prasad, R., Selvaraj, K., 2011. Biogenic synthesis of silver nanoparticles using Nicotiana tobaccum leaf extract and study of their antibacterial effect. Afr. J. Biotechnol. 10, 8122–8130. Suresh, G., Gunasekar, P.H., Kokila, D., Prabhu, D., Dinesh, D., Ravichandran, N., Ramesh, B., Koodalingam, A., Vijaiyan Siva, G., 2014. Green synthesis of silver nanoparticles using Delphinium denudatum root extract exhibits antibacterial and mosquito larvicidal activities. Spectrochim. Acta A Mol. Biomol. Spectrosc. 127 (Suppl C), 61–66. Suresh, D., Shobharani, R.M., Nethravathi, P.C., Pavan Kumar, M.A., Nagabhushana, H., Sharma, S.C., 2015. Artocarpus gomezianus aided green synthesis of ZnO nanoparticles: luminescence, photocatalytic and antioxidant properties. Spectrochim. Acta A Mol. Biomol. Spectrosc. 141 (Suppl C), 128–134. Suriyakalaa, U., Antony, J.J., Suganya, S., Siva, D., Sukirtha, R., Kamalakkannan, S., Pichiah, T., Achiraman, S., 2013. Hepatocurative activity of biosynthesized silver nanoparticles fabricated using Andrographis paniculata. Coll. Surf. B 102, 189–194. Tahir, K., Nazir, S., Li, B., Khan, A.U., Khan, Z.U.H., Gong, P.Y., Khan, S.U., Ahmad, A., 2015. Nerium oleander leaves extract mediated synthesis of gold nanoparticles and its antioxidant activity. Mater. Lett. 156, 198–201. Tan, Y.N., Lee, J.Y., Wang, D.I.C., 2010. Uncovering the design rules for peptide synthesis of metal nanoparticles. J. Am. Chem. Soc. 132 (16), 5677–5686. Tamuly, C., Hazarika, M., Bordoloi, M., 2013. Biosynthesis of Au nanoparticles by Gymnocladus assamicus and its catalytic activity. Mater. Lett. 108 (Supplement C), 276–279. Thema, F.T., Beukes, P., Gurib-Fakim, A., Maaza, M., 2015a. Green synthesis of Monteponite CdO nanoparticles by Agathosma betulina natural extract. J. Alloys Compd. 646 (Suppl C), 1043–1048. Thema, F.T., Manikandan, E., Dhlamini, M.S., Maaza, M., 2015b. Green synthesis of ZnO nanoparticles via Agathosma betulina natural extract. Mater. Lett. 161 (Suppl C), 124–127. Thombre, R., Parekh, F., Patil, N., 2014. Green synthesis of silver nanoparticles using seed extract of Argyreia nervosa. Int. J. Pharm. Bio. Sci. 5 (1), 114–119. Thovhogi, N., Diallo, A., Gurib-Fakim, A., Maaza, M., 2015. Nanoparticles green synthesis by Hibiscus Sabdariffa flower extract: main physical properties. J. Alloys Compd. 647 (Suppl C), 392–396. Thovhogi, N., Park, E., Manikandan, E., Maaza, M., Gurib-Fakim, A., 2016. Physical properties of CdO nanoparticles synthesized by green chemistry via Hibiscus sabdariffa flower extract. J. Alloys Compd. 655 (Suppl C), 314–320. Tran, T.T.T., Vu, T.T.H., Nguyen, T.H., 2013. Biosynthesis of silver nanoparticles using Tithonia diversifolia leaf extract and their antimicrobial activity. Mater. Lett. 105 (Suppl C), 220–223. Udayasoorian, C., Vinoth Kumar, K., Jayabalakrishnan, R.M., 2011. Extracellular synthesis of silver nanoparticles using leaf extract of Cassia auriculata. Dig J Nanomater Biostruct 6, 279–283. Uddin, I., Ahmad, Kh, Khan, A.A., Kazmi, M.A., 2017. Synthesis of silver nanoparticles using Matricaria recutita (Babunah) plant extract and its study as mercury ions sensor. Sens. Biosensing. Res. 16, 62–67. Uma Suganya, K.S., Govindaraju, K., Ganesh Kumar, V., Stalin Dhas, T., Karthick, V., Singaravelu, G., Elanchezhiyan, M., 2015. Blue green alga mediated synthesis of gold nanoparticles and its antibacterial efficacy against Gram positive organisms. Mater. Sci. Eng. C 47 (Suppl C), 351–356. Vaghela, H., Shah, R., Parmar, K., 2017. Biogenic synthesis of silver nanoparticles using bauhinia variegata bark extract and its antibacterial efficacy. Int. J. Nano. Chem. 3, 45–49.

120

3.  Phytosynthesis of Nanoscale Materials

Valodkar, M., Nagar, P.S., Jadeja, R.N., Thounaojam, M.C., Devkar, R.V., Thakore, S., 2011. Euphorbiaceae latex induced green synthesis of non-cytotoxic metallic nanoparticle solutions: a rational approach to antimicrobial applications. Colloids Surf. A Physicochem. Eng. Asp. 384 (1–3), 337–344. Valodkar, M., Rathore, P.S., Jadeja, R.N., Thounaojam, M., Devkar, R.V., Thakore, S., 2012. Cytotoxicity evaluation and antimicrobial studies of starch capped water soluble copper nanoparticles. J. Hazard. Mater. 201 (Suppl C), 244–249. Vanaja, M., Annadurai, G., 2013. Coleus aromaticus leaf extract mediated synthesis of silver nanoparticles and its bactericidal activity. Appl. Nanosci. 3 (3), 217–223. Vanaja, M., Rajeshkumar, S., Paulkumar, K., Gnanajobitha, G., Malarkodi, C., Annadurai, G., 2013. Phytosynthesis and characterization of silver nanoparticles using stem extract of Coleus aromaticus. Int. J. Mat. Biomater. Appl. 3 (1), 1–4. Vanathi, P., Rajiv, P., Narendhran, S., Rajeshwari, S., Rahman, P.K.S.M., Venckatesh, R., 2014. Biosynthesis and characterization of phyto mediated zinc oxide nanoparticles: a green chemistry approach. Mater. Lett. 134 (Suppl C), 13–15. Vankar, P.S., Bajpai, D., 2010. Preparation of gold nanoparticles from Mirabilis jalapa flowers. Indian J. Biochem. Biophys. 47, 157–160. Veerasamy, R., Xin, T.Z., Gunasagaran, S., Xiang, T.F.W., Yang, E.F.C., Jeyakumar, N., Dhanaraj, S.A., 2011. Biosynthesis of silver nanoparticles using mangosteen leaf extract and evaluation of their antimicrobial activities. J. Saudi Chem. Soc. 15 (2), 113–120. Velayutham, K., Rahuman, A.A., Rajakumar, G., Santhoshkumar, T., Marimuthu, S., Jayaseelan, C., Bagavan, A., Kirthi, A.V., Kamaraj, C., Zahir, A.A., Elango, G., 2012. Evaluation of Catharanthus roseus leaf extract-mediated biosynthesis of titanium dioxide nanoparticles against Hippobosca maculata and Bovicola ovis. Parasitol. Res. 111 (6), 2329–2337. Velmurugan, P., Lee, S.-M., Iydroose, M., Lee, K.-J., Oh, B.-T., 2012. Pine cone-mediated green synthesis of silver nanoparticles and their antibacterial activity against agricultural pathogens. Appl. Microbiol. Biotechnol. 97, 361–368. Velmurugan, P., Choa, M., Lim, S.S., Seo, S.K., 2015. Phytosynthesis of silver nanoparticles by Prunus yedoensis leaf extract and their antimicrobial activity. Mater. Lett. 138, 272–275. Venkatesan, J., Manivasagan, P., Kim, S.J., Kirthi, V., Marimuthu, S., Rahuman, A., 2014. Marine algae-mediated synthesis of gold nanoparticles using a novel Ecklonia cava. Bioprocess Biosyst. Eng. 37, 1591–1597. Venkatesham, M., Ayodhya, D., Madhusudhan, A., Veerabhadram, G., 2012. Synthesis of stable silver nanoparticles using gum acacia as reducing and stabilizing agent and study of its microbial properties: a novel green approach. Int. J. Green Nanotechnol. 4 (3), 199–206. Venkateswarlu, P., Ankanna, S., Prasad, T.N.V.K.V., Elumalai, E.K., Nagajyothi, P.C., Savithramma, N., 2010. Green synthesis of silver nanoparticles using Shorea tumbuggaia stem bark. Int. J. Drug Dev. Res. 2, 720–723. Venkatpurwar, V., Pokharkar, V., 2011. Green synthesis of silver nanoparticles using marine polysaccharide: study of in-vitro antibacterial activity. Mater. Lett. 65, 999–1002. Vidhu, V.K., Aromal, S.A., Philip, D., 2011. Green synthesis of silver nanoparticles using Macrotyloma uniflorum. Spectrochim. Acta A Mol. Biomol. Spectrosc. 83 (1), 392–397. Vidya, C., Hiremath, S., Chandraprabha, M.N., Antonyraj, M.A.L., Gopala, I.V., Jain, A., 2013. Green synthesis of ZnO nanoparticles by Calotropis gigantea. Int. J. Curr. Eng. Technol. 1, 118–120. Vijay Kumar, P.P.N., Pammi, S.V.N., Kollu, P., Satyanarayana, K.V.V., Shameem, U., 2014. Green synthesis and characterization of silver nanoparticles using Boerhaavia diffusa plant extract and their anti bacterial activity. Ind. Crop. Prod. 52, 562–566. Vijayakumar, R., Devi, V., Adavallan, K., Saranya, D., 2011. Green synthesis and characterization of gold nanoparticles using extract of anti-tumor potent Crocus sativus. Physica E 44 (3), 665–671. Vijayaraghavan, K., Mahadevan, A., Sathishkumar, M., Pavagadhi, S., Balasubramanian, R., 2011. Biosynthesis of Au(0) from Au(III) via biosorption and bioreduction using brown marine alga Turbinaria conoides. Chem. Eng. J. 167 (1), 223–227. Vijayaraghavan, K., Nalini, S.P.K., Prakash, N.U., Madhankumar, D., 2012. One step green synthesis of silver nano/ microparticles using extracts of Trachyspermum ammi and Papaver somniferum. Colloids Surf. B: Biointerfaces 94 (Suppl C), 114–117. Vilchis-Nestor, A.R., Sánchez-Mendieta, V., Camacho-López, M.A., Gómez-Espinoza, R.M., Camacho-López, M.A., Arenas-Alatorre, J., 2008. Solventless synthesis and optical properties of Au and Ag nanoparticles using Camellia sinensis extract. Mater. Lett. 62, 3103–3105.

REFERENCES 121

Vinod, V.T.P., Saravanan, P., Sreedhar, B., Devi, D.K., Sashidhar, R.B., 2011. A facile synthesis and characterization of Ag, Au and Pt nanoparticles using a natural hydrocolloid gum kondagogu (Cochlospermum gossypium). Colloids Surf. B: Biointerfaces 83 (2), 291–298. Vivek, R., Thangam, R., Muthuchelian, K., Gunasekaran, P., Kaveri, K., Kannan, S., 2012. Green biosynthesis of silver nanoparticles from Annona squamosa leaf extract and its in  vitro cytotoxic effect on MCF-7 cells. Process Biochem. 47 (12), 2405–2410. Wang, Z., An, P., 2017. Characterization of copper complex nanoparticles synthesized by plant polyphenols. bioRxiv. https://doi.org/10.1101/134940. Wang, Y., He, X., Wang, K., Zhang, X., Tan, W., 2009. Barbated Skullcup herb extract-mediated biosynthesis of gold nanoparticles and its primary application in electrochemistry. Colloids Surf. B: Biointerfaces 73 (1), 75–79. Wei, D., Qian, W., 2008. Facile synthesis of Ag and Au nanoparticles utilizing chitosan as a mediator agent. Colloids Surf. B: Biointerfaces 62 (1), 136–142. Wu, W., Huang, J., Wu, L., Sun, D., Lin, L., Zhou, Y., Wang, H., Li, Q., 2013. Two-step size- and shape-separation of biosynthesized gold nanoparticles. Sep. Purif. Technol. 106 (Suppl C), 117–122. Yang, X., Li, Q., Wang, H., Huang, J., Lin, L., Wang, W., Sun, D., Su, Y., Opiyo, J.B., Hong, L., Wang, Y., He, N., Jia, L., 2010. Green synthesis of palladium nanoparticles using broth of Cinnamomum camphora leaf. J. Nanopart. Res. 12 (5), 1589–1598. Yang, N., WeiHong, L., Hao, L., 2014. Biosynthesis of Au nanoparticles using agricultural waste mango peel extract and its in vitro cytotoxic effect on two normal cells. Mater. Lett. 134 (Suppl C), 67–70. Yedurkar, S., Maurya, C., Mahanwar, P., 2016. Biosynthesis of zinc oxide nanoparticles using ixora coccinea leaf extract—a green approach. Open J. Synth. Theory Appl. 05, 1–14. Yilmaz, M., Turkdemir, H., Kilic, M.A., Bayram, E., Cicek, A., Mete, A., Ulug, B., 2011. Biosynthesis of silver nanoparticles using leaves of Stevia rebaudiana. Mater. Chem. Phys. 130 (3), 1195–1202. Yousefzadi, M., Rahimi, Z., Ghafori, V., 2014. The green synthesis, characterization and antimicrobial activities of silver nanoparticles synthesized from green alga Enteromorpha flexuosa (wulfen). J. Agardh. Mater. Lett. 137 (Suppl C), 1–4. Yuvakkumar, R., Suresh, J., Nathanael, A.J., Sundrarajan, M., Hong, S.I., 2014. Novel green synthetic strategy to prepare ZnO nanocrystals using rambutan (Nephelium lappaceum L.) peel extract and its antibacterial applications. Mater. Sci. Eng. C 41 (Suppl C), 17–27. Zahir, A.A., Indira, S.C., 2015. Green synthesis of silver and titanium dioxide nanoparticles using Euphorbia prostrata extract shows shift from apoptosis to G0/G1 arrest followed by necrotic cell death in Leishmania donovani. Antimicrob. Agents Chemother. 59, 4782–4799. Zargar, M., Hamid, A.A., Bakar, F.A., Shamsudin, M.N., Shameli, K., Jahanshiri, F., Farahani, F., 2011. Green synthesis and antibacterial effect of silver nanoparticles using vitex negundo L. Molecules 16 (8), 6667–6676. Zayed, M.F., Eisa, W.H., Shabaka, A.A., 2012. Malva parviflora extract assisted green synthesis of silver nanoparticles. Spectrochim. Acta A Mol. Biomol. Spectrosc. 98 (Suppl. C), 423–428. Zha, J., Dong, C., Wang, X., Zhang, X., Xiao, X., Yang, X., 2017. Green synthesis and characterization of monodisperse gold nanoparticles using Ginkgo Biloba leaf extract. Int. J. Light Electron Opt. 144 (Suppl. C), 511–521.