- Email: [email protected]
Study of Synergistic Effects of Antibiotics And Triangular Shaped Silver Nanoparticles, Synthesized Using UV-Light Irradiation, on S. Aureus and P. Aeruginosa
Available online at www.sciencedirect.com
ScienceDirect Materials Today: Proceedings 18 (2019) 920–927
www.materialstoday.com/proceedings
ICN3I-2017
Study of Synergistic Effects of Antibiotics And Triangular Shaped Silver Nanoparticles, Synthesized Using UV-Light Irradiation, on S. Aureus and P. Aeruginosa Sonali Sahaa, M.M.Malikb, M.S. Qureshic a IES College, Bhopal b, c Department of Physics, M.A.N.I.T., Bhopal, India
Abstract Now days, resistance of bacteria to bactericides and antibiotics has increased. Some antimicrobial agents are extremely irritant and toxic. Hence there is a need to find ways to formulate green and less toxic materials. In the present work, a study of synergistic effects of as-synthesised triangular shaped silver nanoparticles and two standard antibiotics, ampicillin and gentamycin, was studied on Staphylococcus Aureus and Pseudomonas Aeruginosa. A green route is taken to synthesise silver nanoparticles using silver oxalate as precursor; tea extract and chitin as capping and stabilizing agents respectively. A grey coloured colloidal solution of silver nanoparticles is obtained. XRD, TEM and UV-visible spectroscopy, are used tocharacterise the as-synthesised silver colloidal solution. © 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Nanotechnology: Ideas, Innovations & Initiatives-2017 (ICN:3i2017). Keywords:
Silver colloidal solution, Tea extract, UV-Irradiation, Ampicillin and Gentamycin
2214-7853© 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Nanotechnology: Ideas, Innovations & Initiatives-2017 (ICN:3i2017).
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
1.
921
Introduction
Among metal nanoparticles, silver is gaining more attention as it exhibits completely new or improved properties based on specific characteristics such as size distribution and morphology. It is well known from ancient time that silver nanoparticles have very useful biomedical application due to their antibacterial activity. Antibacterial activity of the silver-containing materials can be used, for example, in medicine to reduce infections in burn treatment[1,2] and arthroplasty,[3] as well as to prevent bacteria colonization on prostheses,[4] catheters,[5,6] vascular grafts,[7] dental materials,[8]stainless steel materials,[9] and human skin.[10,11]. At nano scale range this particle size leads to ultra large surface area per mass where a large number of atoms are in immediate contact and available for reaction. The antibacterial activity can be tuned by controlling the size and morphology of nanoparticles. This size, morphology and stability of the metal nanoparticles are strongly influenced by the experimental conditions [12, 13]. Hence, the design of a synthesis method in which the size, morphology, stability and properties are controlled has become a thrust area[14] of research. Previous studies done by researchers on the synthesis and the antibacterial activity of silver nanoparticles, we find that most of the studies are limited upon interaction of spherical silver nanoparticles with bacterial cell wall.[15, 16] The work done by Pal.et.al [17]was the first comparative study of the effect of shape of nanoparticles on bacterial cell. The use of silver had reduced as an anti-infection agent due to the advent of antibiotics and other disinfectants and the poorly understood mechanisms of their toxic effects. However, resistance of bacteria to bactericides and antibiotics has increased in recent years. Some antimicrobial agents are extremely irritant and toxic. Hence there is a need to find ways to formulate green and less toxic materials? Therefore study of the synergistic effects of silver nanoparticles with antibiotics on bacteria has become the requirement of the present time. In the present synthesis route the author has developed a green route by using tea leaf extract as capping agent, UV-irradiation source as a reducing agent and chitin flakes as stabilizing agent to synthesised triangular shaped nanoparticles. Tea, especially black tea, contains antioxidants. The antioxidants contained in tea play a major role in protecting the body against certain illnesses such as cancer and heart ailments. In view of utilizing this property of tea extract the green synthesis process discussed in this paper, uses tea extract as capping agent. Silver oxalate (Ag2C2O4) is photosensitive and yield metallic silver upon the exposure to UV light, those compounds can be photo chemically decomposed to obtain Ag nanoparticles in the presence of capping agents. Previous studies show that antimicrobial formulations of silver in the form of nano particles could be used as effective bactericidal materials. In the present work synergetic effects of silver nanoparticles with antibiotics is being studied against gram positive and gram negative bacteria. 2 Materials and Method 2.1 Chemicals. Materials used for the synthesis of silver nano particles are AR grade silver nitrate (AgNO3) and oxalic acid purchased from Merck, India, Red label tea leaves, deionized water (Ultra pure) and chitin flakes. 2.2 Preparation of silver oxalate Silver oxalate was prepared by mixing 50ml solution of 0.5M AgNO3(Merk,99%) with 30ml of 0.5M oxalic acid (Merk,99%).The white formed precipitate was filtered washed with distilled water, dried in an air oven for one hour and stored in a dark bottle. 2.3 Preparation of tea extract In 50ml volumetric flask was filled up to the mark with boiling water,0.5gm of tea grains were weighed and transferred to this flask and filtered immediately. 2.4 Synthesis of Colloidal Silver nano particles For the synthesis of colloidal solution, 10ml of tea extract is mixed with 0.02 gm of Ag2C2O4 and 20ml doubly distilled water in a three neck round bottom flask and stirred for 35mint in dark. Vacuum is created in the flask followed by UV radiation. During the irradiation process no cut-off filter was used. A plane yellow colloidal
922
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
solution was formed. After this 0.01gm chitin flakes used as stabilizing agent was added to the solution and finally the colour becomes grey. The resultant colloid was washed by centrifugation several times.Fig.1 shows the set up for the above procedure.
Fig.1 Experimental Set-up 3. Results and discussions As-synthesised silver oxalate was characterized using powder XRD using (Rigaku Miniflex II). The lines presented in the powder XRD pattern match the standard sample, primitive monoclinic system. Moreover it is also clear from the XRD graph (shown in fig.2) that no other phase of silver oxalate is present in the as-synthesised silver oxalate.
Fig.2 XRD graph of silver oxalate
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
923
Further characterization was done by SEM (JSM 6390 A Models). The SEM images of as-synthesised silver oxalate is shown in fig.3 (a, b) which indicates irregular shaped particles approximately of size in the range of 500-750 nm.
(a)
(b)
Fig.3 (a, b) SEM images of silver oxalate
Fig.4 XRD pattern of sample (for 30mint of uv-irradiation) The XRD pattern of the sample shown in fig.4 showed that when sample was exposed for different time interval (30 mints),silver oxalate was partially decomposed to generate silver, the main remaining were silver oxalate. Thus the time of UV-irradiation was increased to one hour and further it was observed that silver oxalate decomposed completely. Graph in fig. 5shows pure peaks of pure silver well in accordance with JCPDS file No. 04-0783. The diffraction profile of as-synthesised colloidal silver is fcc and are obviously broadened as compared with bulk silver confirming the formation of silver nanoparticles. Silver oxalate decomposes under UV irradiation to give metallic silver and CO2gas. This is due to the high photosensitivity of Ag2C2O4. [18]. Since this decomposition of Ag2C2O4 is thermodynamically favourable due to the suitable reduction potentials of oxalate [19].This decomposition of oxalate occurs rapidly under UV radiation to yield metallic Ag as shown in Equation given below: Ag2C2O4(s) →Ag(s) +2CO2(g)
924
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
In the presence of UV-irradiation dianion of silver oxalate get excited and thus decomposes into CO2, formation of CO2 can be proved by the appearance of the white precipitate in the baryata solution [20]. To understand the mechanism of the reaction during the decomposition we see that electron is continuously transferred from silver ion to form silver metal [18].This formed silver atoms starts to form particles after getting sufficient concentration.
Fig.5 XRD graph of as-synthesised Ag nano particles for 1hour UV-reduction TEM characterization of the as-synthesized colloidal silver in fig. 6 (a,b) shows formation of triangular silver nanoparticles. The reason for the triangular shaped silver nanoparticles can be attributed to the reason that less time of uv-irradiation leads to slower reduction rate [21]. The average particle size was around 50nm. The size control of metal nano particles is determined by such factors as precursor concentration, molar ratio between surfactant and precursor, as well as the selective absorption of surfactant to different crystal facets [22-23].
(a) (b) Fig.6 (a, b) Tem images of as-synthesised silver nanoparticles for Reduction time 1hr
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
925
After the TEM measurement it becomes also very clear that in the present process tea extract is only acting as capping agent nor as a reducing agent because tea extract is a weak reducing agent [24] and the particle size what we are getting in the present method is not possible by the reduction by weak reducing agent. The next characterisation which was done to characterise the as-synthesised nanoparticles was UV-visible spectroscopy.
Fig.7 UV-visible spectroscopy of as-synthesised nanoparticles for Reduction 1hrs Figure 7 it is very clear that the peak for the graph is nearly at 520nm which is the characteristic peak for triangular shaped silver nanoparticles [25]. 4. Antimicrobial study The bactericidal properties of silver nanoparticles of different shaped were conducted [26]. In the present study antibacterial activity of triangular shaped nanoparticles along with antibiotics ampicillin and gentamicin was tested against Staphylococcus Aureus and Pseudomonas Aeruginosa because triangular nano prism with sharp vertices and edges also display a good antibacterial activity in comparison to other shaped nanoparticles, these nanoparticles can be useful for biomedical applications [27]. As in the present route the shape of the synthesised nanoparticles is triangular which can give best antibacterial result for silver nanoparticles. Zone of inhibition were obtained for the combination of silver nanoparticles and antibiotics. The comparison table of zone of inhibition is shown in table 1. For the comparative study, 1ml of as-synthesized colloidal solution of silver nanoparticles was taken with 10mcg of ampicillin for 15 minutes and the total solution was placed on Soyabean casein digest agar and incubated at 370 C for 48 hrs. The process was repeated with 10mcg of gentamycin.The test was conducted Micro bio laboratory Thane (Maharashtra, India). Table 1-Comparitive study of effect of silver nanoparticles in combination with two antibiotics SR. NO.
ORGANISM
ZONE FOR SAMPLE + AMPICILLIN P1 P2 MEAN
ZONE FOR SAMPLE + GENTAMICIN P1 P2 MEAN
1.
Staphylococcus Aureus
22
20
21
20
18
19
2.
Pseudomonas Aeruginosa
19
23
21
20
16
18
926
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
Plate 1=P1 Plate 2=P2 The mechanism of the bactericidal effect of Ag NPs is that they may attach to the surface of the cell membrane disturbing permeability and respiration functions of the cell [28]. Sharp vertexes and sharp edges of triangular nano prism are more toxic in damaging the bacterial cell [27]. Thus we can summarise from the size of inhibition zone that the as-synthesised sample in combination with ampicillin and gentamicinis equally effective for killing of both the bacteria Staphylococcus Aureus and Pseudomonas Aeruginosa 5. Conclusions In the present work the author to best of her knowledge has tried a new way to synthesise silver nano particle of triangular shape using the basic principle of green technology. The average particle size obtained for the nanoparticles was 50nm. The most important feature of this procedure is that it is free from any chemical process, which satisfies the green biogenic approach of synthesis and gives an edge over various chemical procedures usually applied for the synthesis of silver nanoparticles. A comparative antibacterial study of assynthesised silver nanoparticles in combination with two standard antibiotics was analysed for a gram positive and a gram negative bacteria and it was found that sample in combination with ampicillin and gentamicin are equally effective for both the bacteria. Acknowledgement Author is thankful to the Director, M.A.N.I.T., Bhopal, India for the facilities at the institute, AMPRI Bhopal for XRD Bhopal, for providing XRD facility, HSADL, Bhopal for the TEM facility, Civil Engineering department M.A.N.I.T., Bhopal for providing UV vis-spectrophotometer facility. I am thankful to all my colleagues for the valuable help and suggestions. References [1] Ulkur, E.; Oncul, O.; Karagoz, H.; Yeniz, E.; Celikoz, B. Burns 2005, 31, 874. [2] Parikh, D. V., Fink, T., Raja sekharan, K., Sachinvala, N. D., Sawhney A. P. S., Calamari, T. A., Parikh, A. D., “Antimicrobial silver/sodium carboxy methyl cotton dressings ressings for burn wound”, 75 (2005) ,pp. 134-138. [3] Alt, V., Bechert, T., Steinrucke, P., Wagener, M., Seidel, P., Dingeldein, E., Domann, U., Schnettler, R., “An in vitro assessment of the antibacterial properties and cytotoxicity of nanoparticulate silver bone cement”, Biomaterials, 25 (2004), 4383–4391. [4] Gosheger, G.; Hardes, J.; Ahrens, H.; Streit burger, A.; Buerger, H.; Erren, M.; Gunsel, A.; Kemper, F. H.; Winkelmann, W.; Eiff, Ch. Biomaterials 2004, 25, 5547 [5] Rupp, M. E.; Fitzgerald, T.; Marion, N.; Helget, V.; Puumala, S.; Anderson, J. R.; Fey, P. D. Am. J. Infect. Control, 32,( 2004) , pp- 445. [6] Samuel, U., Guggenbichler, J. P., “Prevention of catheter-related infections: the potential of a new nano-silver impregnated cathete”, Int. J. Antimicrob. Agents, 23, S1 (2004), S75-8. [7] Strathmann, M.; Wingender, J. Int. J. Antimicrob. Agents 2004, 24, 36. [8] Ohashi, S.,Saku, S., Yamamoto, K. J. Oral Rehabil, “Antibacterial activity of silver inorganic agent”, 31, (2004), pp.-364-367. [9] Bosetti. M., Masse A., Tobin E., Cannas M., “Silver coated materials for external fixation devices: in vitro biocompatibility and genotoxicity”, Biomaterials, 23, (2002), pp.-887892.
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
927
[10] Gauger A., Mempel M., Schekatz A., Schafer T., Ring J., Abeck D., “Silver-coated textiles reduce Staphylococcus Aureus colonization in patients with atopic eczema”, Dermatology, 207 (1), (2003), pp.-15-21. [11] Lee H. J., Jeong S. H., “Bacteriostasis and skin innoxiousness of nano size silver colloids on textile fabrics”, Text. Res. J., 75,(2005), pp.-551-556. [12]Knoll B, Keilmann F., “Near-field probing of vibrational absorption for chemical microscopy”, Nature, 399,(1999), pp.-134-137. [13]Sengupta S, Eavarone D, Capila I, Zhao GL, Watson N, Kiziltepe T, et al., “Temporal Targeting of tumor cells and neovasculature with a nano scale delivery system”, Nature, 436, 7050 (2005),pp.-568-572 [14]Wiley B, Sun Y, Xia Y., Acc Chem Res,40,(2007), pp.-1067. [15]Afreen, R.V., Ranganath, E., “Synthesis of mono dispersed silver nanoparticles by Rhizopus Stolonifer and its antibacterial activity against MDR strains of Pseudomonas Aeruginosa fromburnt patients”, Int. J. Environ. Sci., 1(7), (2011),pp.-1582–1592. [16] Mirzajani, F., Ghassempour, A., Aliahmadi, A., Esmaeili, M.A., “Antibacterial effect of silver nanoparticles on Staphylococcus aureus”, Research. Microbiol, 162, (2011), pp. – 542–549. [17] Pal, S., Tak, Y., Song, J., “Does the antibacterial activity of silver nanoparticle depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. App.”, Environ. Microbial, 73(6), (2007), pp. - 1712–1720. [18] V.V. Boldyrev, “Thermal decomposition of silver oxalate”, Thermol. Chim. Acta, 388, (2002), pp.-63-90. [19]S. Navaladian, C.M. Janet, B. Viswanathan, T.K. Varadarajan, R.P. Viswanath, “A facile room temperature synthesis of gold nanowires by oxalate reduction method”, J. Phys. Chem. C, 111,(2007), 14150-14156. [20] S. Navaladian, B. Viswanathan, R.P. Viswanath, T.K. Varadarajan,“Thermal decomposition as route for silver nanoparticles,” Nanoscale Res. Lett., 2,1, (2007), pp. 44-48. [21] Seyed Soheil Mansouri, Sattar Ghader, “Experimental study on effect of different parameters on size and shape of triangular silver nanoparticles prepared by a simple and rapid method in aqueous solution’ , Arabian Journal of Chemistry,2, (2009) , pp.-47– 53. [22] Kasivelu G., Sabjan K., Vijayakumar Ganesh K., Ganesan S., “Silver, gold and bimetallicnanoparticles production using single-cell protein (Spirulina platensis) Geitler”, J Mater Sci., 43, (2008), pp. - 5115–5122. [23] Godapati R. D., Cong. Luso-esparnfarm 3 (187) (1954). [24] Yuet Ying Loo, Buong Woei Chieng, Mitsuaki Nishibuchi Son Radu “Synthesis of silver nanoparticles by using tea leaf extract from Camellia Sinensis”, International Journal of Nanomedicine, 7,(2012), pp.- 4263–4267. [25] M Joshi, A Bhattacharyya and S Wazed Ali, “Characterization techniques for Nanotechnologyapplications in textiles”, Indian journal of fibre and textile research”,33,(2008), pp.- 304-317. [26] Pal, S., Tak, Y., Song, J., “Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. App.”, Environ. Microbial, 73(6), (2007), pp. - 1712–1720. [27] Pham Van Dong, Chu Hoang Ha, Le Tran Binh and Jörn Kasbohm, “Chemical synthesis and antibacterial activity of novel-shaped silver nanoparticles”, International Nano Letters, 2,9,(2012). [28]Kvitek L, Panacek A, Soukupova J, Kolar M, Vecerova R, Prucek R, et al. J Phys Chem. C., 112,(2008), pp.5825.
ScienceDirect Materials Today: Proceedings 18 (2019) 920–927
www.materialstoday.com/proceedings
ICN3I-2017
Study of Synergistic Effects of Antibiotics And Triangular Shaped Silver Nanoparticles, Synthesized Using UV-Light Irradiation, on S. Aureus and P. Aeruginosa Sonali Sahaa, M.M.Malikb, M.S. Qureshic a IES College, Bhopal b, c Department of Physics, M.A.N.I.T., Bhopal, India
Abstract Now days, resistance of bacteria to bactericides and antibiotics has increased. Some antimicrobial agents are extremely irritant and toxic. Hence there is a need to find ways to formulate green and less toxic materials. In the present work, a study of synergistic effects of as-synthesised triangular shaped silver nanoparticles and two standard antibiotics, ampicillin and gentamycin, was studied on Staphylococcus Aureus and Pseudomonas Aeruginosa. A green route is taken to synthesise silver nanoparticles using silver oxalate as precursor; tea extract and chitin as capping and stabilizing agents respectively. A grey coloured colloidal solution of silver nanoparticles is obtained. XRD, TEM and UV-visible spectroscopy, are used tocharacterise the as-synthesised silver colloidal solution. © 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Nanotechnology: Ideas, Innovations & Initiatives-2017 (ICN:3i2017). Keywords:
Silver colloidal solution, Tea extract, UV-Irradiation, Ampicillin and Gentamycin
2214-7853© 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Nanotechnology: Ideas, Innovations & Initiatives-2017 (ICN:3i2017).
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
1.
921
Introduction
Among metal nanoparticles, silver is gaining more attention as it exhibits completely new or improved properties based on specific characteristics such as size distribution and morphology. It is well known from ancient time that silver nanoparticles have very useful biomedical application due to their antibacterial activity. Antibacterial activity of the silver-containing materials can be used, for example, in medicine to reduce infections in burn treatment[1,2] and arthroplasty,[3] as well as to prevent bacteria colonization on prostheses,[4] catheters,[5,6] vascular grafts,[7] dental materials,[8]stainless steel materials,[9] and human skin.[10,11]. At nano scale range this particle size leads to ultra large surface area per mass where a large number of atoms are in immediate contact and available for reaction. The antibacterial activity can be tuned by controlling the size and morphology of nanoparticles. This size, morphology and stability of the metal nanoparticles are strongly influenced by the experimental conditions [12, 13]. Hence, the design of a synthesis method in which the size, morphology, stability and properties are controlled has become a thrust area[14] of research. Previous studies done by researchers on the synthesis and the antibacterial activity of silver nanoparticles, we find that most of the studies are limited upon interaction of spherical silver nanoparticles with bacterial cell wall.[15, 16] The work done by Pal.et.al [17]was the first comparative study of the effect of shape of nanoparticles on bacterial cell. The use of silver had reduced as an anti-infection agent due to the advent of antibiotics and other disinfectants and the poorly understood mechanisms of their toxic effects. However, resistance of bacteria to bactericides and antibiotics has increased in recent years. Some antimicrobial agents are extremely irritant and toxic. Hence there is a need to find ways to formulate green and less toxic materials? Therefore study of the synergistic effects of silver nanoparticles with antibiotics on bacteria has become the requirement of the present time. In the present synthesis route the author has developed a green route by using tea leaf extract as capping agent, UV-irradiation source as a reducing agent and chitin flakes as stabilizing agent to synthesised triangular shaped nanoparticles. Tea, especially black tea, contains antioxidants. The antioxidants contained in tea play a major role in protecting the body against certain illnesses such as cancer and heart ailments. In view of utilizing this property of tea extract the green synthesis process discussed in this paper, uses tea extract as capping agent. Silver oxalate (Ag2C2O4) is photosensitive and yield metallic silver upon the exposure to UV light, those compounds can be photo chemically decomposed to obtain Ag nanoparticles in the presence of capping agents. Previous studies show that antimicrobial formulations of silver in the form of nano particles could be used as effective bactericidal materials. In the present work synergetic effects of silver nanoparticles with antibiotics is being studied against gram positive and gram negative bacteria. 2 Materials and Method 2.1 Chemicals. Materials used for the synthesis of silver nano particles are AR grade silver nitrate (AgNO3) and oxalic acid purchased from Merck, India, Red label tea leaves, deionized water (Ultra pure) and chitin flakes. 2.2 Preparation of silver oxalate Silver oxalate was prepared by mixing 50ml solution of 0.5M AgNO3(Merk,99%) with 30ml of 0.5M oxalic acid (Merk,99%).The white formed precipitate was filtered washed with distilled water, dried in an air oven for one hour and stored in a dark bottle. 2.3 Preparation of tea extract In 50ml volumetric flask was filled up to the mark with boiling water,0.5gm of tea grains were weighed and transferred to this flask and filtered immediately. 2.4 Synthesis of Colloidal Silver nano particles For the synthesis of colloidal solution, 10ml of tea extract is mixed with 0.02 gm of Ag2C2O4 and 20ml doubly distilled water in a three neck round bottom flask and stirred for 35mint in dark. Vacuum is created in the flask followed by UV radiation. During the irradiation process no cut-off filter was used. A plane yellow colloidal
922
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
solution was formed. After this 0.01gm chitin flakes used as stabilizing agent was added to the solution and finally the colour becomes grey. The resultant colloid was washed by centrifugation several times.Fig.1 shows the set up for the above procedure.
Fig.1 Experimental Set-up 3. Results and discussions As-synthesised silver oxalate was characterized using powder XRD using (Rigaku Miniflex II). The lines presented in the powder XRD pattern match the standard sample, primitive monoclinic system. Moreover it is also clear from the XRD graph (shown in fig.2) that no other phase of silver oxalate is present in the as-synthesised silver oxalate.
Fig.2 XRD graph of silver oxalate
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
923
Further characterization was done by SEM (JSM 6390 A Models). The SEM images of as-synthesised silver oxalate is shown in fig.3 (a, b) which indicates irregular shaped particles approximately of size in the range of 500-750 nm.
(a)
(b)
Fig.3 (a, b) SEM images of silver oxalate
Fig.4 XRD pattern of sample (for 30mint of uv-irradiation) The XRD pattern of the sample shown in fig.4 showed that when sample was exposed for different time interval (30 mints),silver oxalate was partially decomposed to generate silver, the main remaining were silver oxalate. Thus the time of UV-irradiation was increased to one hour and further it was observed that silver oxalate decomposed completely. Graph in fig. 5shows pure peaks of pure silver well in accordance with JCPDS file No. 04-0783. The diffraction profile of as-synthesised colloidal silver is fcc and are obviously broadened as compared with bulk silver confirming the formation of silver nanoparticles. Silver oxalate decomposes under UV irradiation to give metallic silver and CO2gas. This is due to the high photosensitivity of Ag2C2O4. [18]. Since this decomposition of Ag2C2O4 is thermodynamically favourable due to the suitable reduction potentials of oxalate [19].This decomposition of oxalate occurs rapidly under UV radiation to yield metallic Ag as shown in Equation given below: Ag2C2O4(s) →Ag(s) +2CO2(g)
924
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
In the presence of UV-irradiation dianion of silver oxalate get excited and thus decomposes into CO2, formation of CO2 can be proved by the appearance of the white precipitate in the baryata solution [20]. To understand the mechanism of the reaction during the decomposition we see that electron is continuously transferred from silver ion to form silver metal [18].This formed silver atoms starts to form particles after getting sufficient concentration.
Fig.5 XRD graph of as-synthesised Ag nano particles for 1hour UV-reduction TEM characterization of the as-synthesized colloidal silver in fig. 6 (a,b) shows formation of triangular silver nanoparticles. The reason for the triangular shaped silver nanoparticles can be attributed to the reason that less time of uv-irradiation leads to slower reduction rate [21]. The average particle size was around 50nm. The size control of metal nano particles is determined by such factors as precursor concentration, molar ratio between surfactant and precursor, as well as the selective absorption of surfactant to different crystal facets [22-23].
(a) (b) Fig.6 (a, b) Tem images of as-synthesised silver nanoparticles for Reduction time 1hr
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
925
After the TEM measurement it becomes also very clear that in the present process tea extract is only acting as capping agent nor as a reducing agent because tea extract is a weak reducing agent [24] and the particle size what we are getting in the present method is not possible by the reduction by weak reducing agent. The next characterisation which was done to characterise the as-synthesised nanoparticles was UV-visible spectroscopy.
Fig.7 UV-visible spectroscopy of as-synthesised nanoparticles for Reduction 1hrs Figure 7 it is very clear that the peak for the graph is nearly at 520nm which is the characteristic peak for triangular shaped silver nanoparticles [25]. 4. Antimicrobial study The bactericidal properties of silver nanoparticles of different shaped were conducted [26]. In the present study antibacterial activity of triangular shaped nanoparticles along with antibiotics ampicillin and gentamicin was tested against Staphylococcus Aureus and Pseudomonas Aeruginosa because triangular nano prism with sharp vertices and edges also display a good antibacterial activity in comparison to other shaped nanoparticles, these nanoparticles can be useful for biomedical applications [27]. As in the present route the shape of the synthesised nanoparticles is triangular which can give best antibacterial result for silver nanoparticles. Zone of inhibition were obtained for the combination of silver nanoparticles and antibiotics. The comparison table of zone of inhibition is shown in table 1. For the comparative study, 1ml of as-synthesized colloidal solution of silver nanoparticles was taken with 10mcg of ampicillin for 15 minutes and the total solution was placed on Soyabean casein digest agar and incubated at 370 C for 48 hrs. The process was repeated with 10mcg of gentamycin.The test was conducted Micro bio laboratory Thane (Maharashtra, India). Table 1-Comparitive study of effect of silver nanoparticles in combination with two antibiotics SR. NO.
ORGANISM
ZONE FOR SAMPLE + AMPICILLIN P1 P2 MEAN
ZONE FOR SAMPLE + GENTAMICIN P1 P2 MEAN
1.
Staphylococcus Aureus
22
20
21
20
18
19
2.
Pseudomonas Aeruginosa
19
23
21
20
16
18
926
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
Plate 1=P1 Plate 2=P2 The mechanism of the bactericidal effect of Ag NPs is that they may attach to the surface of the cell membrane disturbing permeability and respiration functions of the cell [28]. Sharp vertexes and sharp edges of triangular nano prism are more toxic in damaging the bacterial cell [27]. Thus we can summarise from the size of inhibition zone that the as-synthesised sample in combination with ampicillin and gentamicinis equally effective for killing of both the bacteria Staphylococcus Aureus and Pseudomonas Aeruginosa 5. Conclusions In the present work the author to best of her knowledge has tried a new way to synthesise silver nano particle of triangular shape using the basic principle of green technology. The average particle size obtained for the nanoparticles was 50nm. The most important feature of this procedure is that it is free from any chemical process, which satisfies the green biogenic approach of synthesis and gives an edge over various chemical procedures usually applied for the synthesis of silver nanoparticles. A comparative antibacterial study of assynthesised silver nanoparticles in combination with two standard antibiotics was analysed for a gram positive and a gram negative bacteria and it was found that sample in combination with ampicillin and gentamicin are equally effective for both the bacteria. Acknowledgement Author is thankful to the Director, M.A.N.I.T., Bhopal, India for the facilities at the institute, AMPRI Bhopal for XRD Bhopal, for providing XRD facility, HSADL, Bhopal for the TEM facility, Civil Engineering department M.A.N.I.T., Bhopal for providing UV vis-spectrophotometer facility. I am thankful to all my colleagues for the valuable help and suggestions. References [1] Ulkur, E.; Oncul, O.; Karagoz, H.; Yeniz, E.; Celikoz, B. Burns 2005, 31, 874. [2] Parikh, D. V., Fink, T., Raja sekharan, K., Sachinvala, N. D., Sawhney A. P. S., Calamari, T. A., Parikh, A. D., “Antimicrobial silver/sodium carboxy methyl cotton dressings ressings for burn wound”, 75 (2005) ,pp. 134-138. [3] Alt, V., Bechert, T., Steinrucke, P., Wagener, M., Seidel, P., Dingeldein, E., Domann, U., Schnettler, R., “An in vitro assessment of the antibacterial properties and cytotoxicity of nanoparticulate silver bone cement”, Biomaterials, 25 (2004), 4383–4391. [4] Gosheger, G.; Hardes, J.; Ahrens, H.; Streit burger, A.; Buerger, H.; Erren, M.; Gunsel, A.; Kemper, F. H.; Winkelmann, W.; Eiff, Ch. Biomaterials 2004, 25, 5547 [5] Rupp, M. E.; Fitzgerald, T.; Marion, N.; Helget, V.; Puumala, S.; Anderson, J. R.; Fey, P. D. Am. J. Infect. Control, 32,( 2004) , pp- 445. [6] Samuel, U., Guggenbichler, J. P., “Prevention of catheter-related infections: the potential of a new nano-silver impregnated cathete”, Int. J. Antimicrob. Agents, 23, S1 (2004), S75-8. [7] Strathmann, M.; Wingender, J. Int. J. Antimicrob. Agents 2004, 24, 36. [8] Ohashi, S.,Saku, S., Yamamoto, K. J. Oral Rehabil, “Antibacterial activity of silver inorganic agent”, 31, (2004), pp.-364-367. [9] Bosetti. M., Masse A., Tobin E., Cannas M., “Silver coated materials for external fixation devices: in vitro biocompatibility and genotoxicity”, Biomaterials, 23, (2002), pp.-887892.
S. Saha et al. / Materials Today: Proceedings 18 (2019) 920–927
927
[10] Gauger A., Mempel M., Schekatz A., Schafer T., Ring J., Abeck D., “Silver-coated textiles reduce Staphylococcus Aureus colonization in patients with atopic eczema”, Dermatology, 207 (1), (2003), pp.-15-21. [11] Lee H. J., Jeong S. H., “Bacteriostasis and skin innoxiousness of nano size silver colloids on textile fabrics”, Text. Res. J., 75,(2005), pp.-551-556. [12]Knoll B, Keilmann F., “Near-field probing of vibrational absorption for chemical microscopy”, Nature, 399,(1999), pp.-134-137. [13]Sengupta S, Eavarone D, Capila I, Zhao GL, Watson N, Kiziltepe T, et al., “Temporal Targeting of tumor cells and neovasculature with a nano scale delivery system”, Nature, 436, 7050 (2005),pp.-568-572 [14]Wiley B, Sun Y, Xia Y., Acc Chem Res,40,(2007), pp.-1067. [15]Afreen, R.V., Ranganath, E., “Synthesis of mono dispersed silver nanoparticles by Rhizopus Stolonifer and its antibacterial activity against MDR strains of Pseudomonas Aeruginosa fromburnt patients”, Int. J. Environ. Sci., 1(7), (2011),pp.-1582–1592. [16] Mirzajani, F., Ghassempour, A., Aliahmadi, A., Esmaeili, M.A., “Antibacterial effect of silver nanoparticles on Staphylococcus aureus”, Research. Microbiol, 162, (2011), pp. – 542–549. [17] Pal, S., Tak, Y., Song, J., “Does the antibacterial activity of silver nanoparticle depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. App.”, Environ. Microbial, 73(6), (2007), pp. - 1712–1720. [18] V.V. Boldyrev, “Thermal decomposition of silver oxalate”, Thermol. Chim. Acta, 388, (2002), pp.-63-90. [19]S. Navaladian, C.M. Janet, B. Viswanathan, T.K. Varadarajan, R.P. Viswanath, “A facile room temperature synthesis of gold nanowires by oxalate reduction method”, J. Phys. Chem. C, 111,(2007), 14150-14156. [20] S. Navaladian, B. Viswanathan, R.P. Viswanath, T.K. Varadarajan,“Thermal decomposition as route for silver nanoparticles,” Nanoscale Res. Lett., 2,1, (2007), pp. 44-48. [21] Seyed Soheil Mansouri, Sattar Ghader, “Experimental study on effect of different parameters on size and shape of triangular silver nanoparticles prepared by a simple and rapid method in aqueous solution’ , Arabian Journal of Chemistry,2, (2009) , pp.-47– 53. [22] Kasivelu G., Sabjan K., Vijayakumar Ganesh K., Ganesan S., “Silver, gold and bimetallicnanoparticles production using single-cell protein (Spirulina platensis) Geitler”, J Mater Sci., 43, (2008), pp. - 5115–5122. [23] Godapati R. D., Cong. Luso-esparnfarm 3 (187) (1954). [24] Yuet Ying Loo, Buong Woei Chieng, Mitsuaki Nishibuchi Son Radu “Synthesis of silver nanoparticles by using tea leaf extract from Camellia Sinensis”, International Journal of Nanomedicine, 7,(2012), pp.- 4263–4267. [25] M Joshi, A Bhattacharyya and S Wazed Ali, “Characterization techniques for Nanotechnologyapplications in textiles”, Indian journal of fibre and textile research”,33,(2008), pp.- 304-317. [26] Pal, S., Tak, Y., Song, J., “Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. App.”, Environ. Microbial, 73(6), (2007), pp. - 1712–1720. [27] Pham Van Dong, Chu Hoang Ha, Le Tran Binh and Jörn Kasbohm, “Chemical synthesis and antibacterial activity of novel-shaped silver nanoparticles”, International Nano Letters, 2,9,(2012). [28]Kvitek L, Panacek A, Soukupova J, Kolar M, Vecerova R, Prucek R, et al. J Phys Chem. C., 112,(2008), pp.5825.