- Email: [email protected]
Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts
Accepted Manuscript Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts F.B. Moreno-Luna, A. Tovar-Corona, J.L. Herrera-Perez, J. Santoyo-Salazar, E. Rubio-Rosas, O. Vázquez-Cuchillo PII: DOI: Reference:
S0167-577X(18)31511-8 https://doi.org/10.1016/j.matlet.2018.09.122 MLBLUE 24990
To appear in:
Materials Letters
Received Date: Accepted Date:
13 November 2017 21 September 2018
Please cite this article as: F.B. Moreno-Luna, A. Tovar-Corona, J.L. Herrera-Perez, J. Santoyo-Salazar, E. RubioRosas, O. Vázquez-Cuchillo, Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts, Materials Letters (2018), doi: https://doi.org/10.1016/j.matlet.2018.09.122
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts
F.B. Moreno-Luna1, A. Tovar-Corona2, J. L. Herrera-Perez1, J. Santoyo-Salazar3, E. RubioRosas4, O. Vázquez-Cuchillo5 *. 1 Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas, IPN. Av. Instituto Politécnico Nacional, 2580. Barrio Laguna Ticomán, C.P. 07340, CDMEX, México. 2 Universidad Politécnica Metropolitana de Puebla. Ingeniería en Biotecnología. Popocatépetl S/N, Tres Cerritos, C.P 72480, Puebla, México. 3 Departamento de Física CINVESTAV-IPN Apartado postal 14-740, C.P. 07360, CDMEX, México. 4 Benemérita Universidad Autónoma de Puebla, Facultad de Ingeniería Química, Avenida San Claudio y 18 Sur, C.P. 72570 Puebla, Puebla, México. 5 Instituto Tecnológico de Puebla, Departamento de Ciencias Básicas. Av. Tecnológico #420 Col. Maravillas, C.P. 72220, Puebla, México.
*Corresponding autor: [email protected]
Abstract: Gold nanoparticles were synthetized in short time by a novel and easy method by using an aqueous extract from Agave potatorum. The UV-Vis data show a characteristic band at 540 nm, from the minute 2 of synthesis that intensifies through the reaction time advances, by XRay diffraction and Selective Area Electronic Diffraction patterns, it is demonstrated the polycrystallinity of the samples, exhibiting the specific features of metallic gold; the Transmission Electronic Microscopy results show pseudospherical nanoparticles with an average size of 14 nm corresponding to the synthesized samples at 10 min and 22 nm in the case of the synthesized samples at 20 min. The results suggest that the Agave extract works also as stabilizer.
Keywords: Nanoparticles Au (0), Agave potatorum; Quick biosynthesis; Colloidal metal particles.
I.
Introduction
In the last decade, the development of new technologies to synthesize nanomaterials [1] have been addressed towards the objective of magnifying its properties in order; to be employed in multiple fields [2]. For instance, in the case of medicine area it is required to obtain nanomaterials possessing a strong affinity between the synthesized nanoparticles and the patient tissues, allowing to increase the effect that is wanted to be strengthen [3, 4], something very important that does not occur employing the current synthesis routes, mainly due to the toxic residues that remain attached to the nanoparticles surface [5]. Therefore, to
obtain better and more efficient results in biological applications it is needed the development of new techniques that allow those “biological-friendly” properties. Consequently, in recent years new nanoparticles synthesis methods have been developed, by using biotechnological procedures, employing microorganisms [6] and reductants from biological sources [7,8] which main purpose is to avoid the formation of the toxic substances that trigger rejection. Hence in the present study, it has been scouted the biosynthesis of gold nanoparticles (BioAuNP’s) by using a new methodology, that employs selective extracts obtained from Agave potatorum biomass, the nanoparticles are synthesized in short times and low temperature, with high stability and a big potential to be employed in biological applications.
II.
Materials and methods
a. Agave potatorum extract preparation In order to prepare the aqueous extract, 100 g of basal leaves from seven years old Agave potatorum plants were cut from cultivated specimens. The germplasm used to grow the plants was obtained from Tepanco de López, Puebla (N 18°30’41.476”, O 97°34’33.711”). The leaves used were carefully washed, sliced in small pieces and then macerated, the resultant liquid was filtrated with Whatman paper No.1, finally it was maintained at 4°C in the fridge. b. Biogenic AuNP’s synthesis Biogenic gold nanoparticles synthesis was performed by mixing 0.5 ml of extract with 9.5 ml of 1.0 mM HAuCl4 (Sigma-Aldrich 99.9%) solution. The resulting mixture was heated under reflux at 60°C, sampling aliquots from the minute 1 to 30. The obtained BioAuNP’s were maintained in darkness and refrigeration at 4 °C until use.
c. Characterization. UV-Vis spectra were recorded on a Perkin-Elmer lambda 35. The AuNP’s morphology, Transmission Electronic Microscopy (TEM) analysis, High Resolution TEM and the Selected Area Electronic Diffraction (SAED) pattern were obtained from JEOL, JEM-2010 microscope operated at 200 kV. To achieve the analysis, a drop of the samples was deposited in TEM copper grids carbon covered, letting it to evaporate at room temperature. The X ray diffraction (XRD) analysis were performed in a D8 Bruker Discover Series 2 diffractometer with Cu Kα radiation.
III.
Results and discussion
In Figure 1 (b-h), the UV-Vis spectra obtained during the first 30 minutes of synthesis are shown, observing from minute 2 the characteristic band at AuNPs near 540 nm, which is intensified by increasing the reaction time [9], this increase is related to the spread in size due to the nucleation process of the AuNPs [10]; The spectrum shows the characteristic signals of the agave extract used as a reductant during the synthesis and does not present any signal close to the characteristic band of the superficial plasmon of the AuNP’s. Evidence of the reduction of Au+ to Au0 ions was shown by changing the coloration of Chloroauric acid solution (HAuCl4) by turning from light yellow to violet (Figure inserted), initiating this change in approximately 2 minutes, which indicates the rapid reduction of Au + ions to their elemental metallic form, with their subsequent aggregation to form gold nanoparticles (AuNP´s). This reduction of Au ions is probably carried out by the large amount of organic matter with reducing characteristics such as saponins and terpenoids present in the Agave potatorum solution [11-13]. The XRD analyzes of the AuNPs sample synthesized at 10 min
are shown in Figure 2a, observing only reflections at 38.20 °, 44.40 °, 64.60 °, 77.60 ° and 81.76 °, such reflections are indexed to planes (111), (200), (220), (311) and (222) of the cubic structure centered on the faces (FCC) of the metal Au (JCPDS 001-2616). Similar reflections are observed for the sample synthesized for 30 min (figure 2b), In both diffractograms no characteristic signals were detected to gold oxide. Figure 3 shows the TEM images of the nanoparticles synthesized at 60 ° C for 10 min. observing a pseudospherical morphology, with an average diameter of 14 nm (inserted). However, the materials obtained at 30 minutes (at the same temperature of 60 ° C) are shown in Figure 4 with an average size of 22 nm (inserted). The interplanar distance of the samples synthesized at 10 and 30 minutes are shown in Figure 3b and 4b, which is close to 0.233 nm corresponding to the distance from the plane (111) of gold (0). This result joined to the electron diffraction patterns (TED) (Figure 3c and 4c) confirms the high crystallinity of the AuNPs obtained by this synthetic route. The pseudospherical form of the AuNP’s may be due to the presence of organic compounds that perform the surfactant function [14], such as the present saponins in the used extract, this situation can be confirmed in the future with other studies.
IV.
Conclusions
A method of biosynthesis of Au nanoparticles using extracts of the xerophytic plant, Agave potatorum, was developed, obtaining the nanomaterials in short times and low temperature (60 °C) of synthesis. The TEM results showed that pseudospherical Au nanoparticles having a size of 14 nm were obtained at 10 minutes of reaction, this size is increased to 22 nm after 30 min of reaction. By UV-Vis spectroscopy, it was shown that the reduction starts from minute 2 of the reaction, evidenced by the band at 540 nm that increases with the time of
synthesis. The results by HRTEM, XRD and TED show that the AuNPs are in the cubic phase centered on the faces (fcc) of Au (0). The reductant developed a stabilizer-surfactant functionality, allowing to modify the size of the synthesized AuNP´s to change the synthesis time.
V.
Acknowledgements
This research was supported by the projects PRODEP DSA/103.5/15/7495, TecMEX 5833.16-P, PRODEP IDCA 23898, SECITI-CDMX México (Grant No. 071-2016), SEPIUPIITA (SIP 20162015)
Bibliography. [1]
Hasan S., (2015) A Review on Nanoparticles: Their Synthesis and Types. Research Journal of Recent Sciences. Vol. 4, 1-3.
[2]
Heera, P., & Shanmugam, S. (2015) Nanoparticle characterization and application: an overview. Int.J.Curr.Microbiol.App.Sci. 4(8), 379-386.
[3]
Wang E., Wang A., (2014) Nanoparticles and their applications in cell and molecular biology. Integr. Biol. 6, 9-26.
[4]
Min J., Bee E., Seop M., Bae B., Jung T., (2015) Self-assembly of biogenic gold nanoparticles and their use to enhance drug delivery into cells. Colloids and Surfaces B: Biointerfaces. Volume 135 (1), 27-34.
[5]
Sharma D. et al., (2015) Biogenic synthesis of nanoparticles: A review. Arabian Journal of Chemistry. http://dx.doi.org/10.1016/j. arabjc.2015.11.002
[6]
Kitching M., Ramani M & Marsili E. (2014) Fungal biosynthesis of gold nanoparticles: mechanism and scale up. Microbial Biotechnology 8, 904-917.
[7]
Mittal A. K., Chisti Y., Banerjee U. C. (2013) Synthesis of metallic nanoparticles using plant extracts. Biotechnol Adv. 31(2), 346–356.
[8]
A. Tovar-Corona, M.A. Lobo-Sánchez, J.L. Herrera-Perez, R. Zanella, J.I. RodriguezMora, O. Vázquez-Cuchillo, (2018) Green synthesis of copper (0) nanoparticles with cyanidine-O-3-glucoside and its strong antimicrobial activity. Materials Letters 211 (2018) 266–269.
[9]
Britto R., Cortez M., Ramírez L., Larios E., Alvarez R., Rocha O., Delgado Y., Nuñez C., Arizpe H., Hernández A., Flores M., (2016) Instant synthesis of gold nanoparticles at room temperature and SERS applications. Physics Letters A, 380(34), 2658-2663.
[10]
Haiss W., Thanh N. T. K., Aveyard J. & Ferning D. G. (2007) Determination of size and concentration of Gold nanoparticles from UV-Vis spectra. Analytical Chemistry, 79(11) 4215-4221.
[11]
Rizwan K., Zubair M., Rasool N., Riaz M., Zia-Ul-Haq M., De Feo V. (2012) Phytochemical and Biological Studies of Agave attenuata. International Journal of Molecular Sciences, 13, 6440-6451.
[12]
Santos H.J.L., (2008), Identificación y cuantificación de terpenos en Agave mezcalero por microextracción, en fase scci, (2008), Facultad de Química UNAM
[13]
Sidana J., Singh B., Sharma O. P., (2016), Saponins of Agave. Chemistry and bioactivity, Phytochemistry, 160, 22-46.
[14]
Gonzalez L., Almaraz N., Proal J., Robles F., Del Toro G., Quintos M., (2013) Surfactant properties of the saponins of Agave Durangensis, application on arsenic removal. International Journal of Engineering and Applied Sciences, 4(2), 87-94.
Absorbance (u.a.)
FIGURES.
a) Agave extract b) 1 min c) 2 min d) 3 min e) 4 min f) 5 min g) 10 min h) 30 min
h g f e d c a b 400
450
500
550
600
650
700
Wavelength (nm) Figure 1. The typical UV–vis spectra a) Agave extract. b-h) Gold nanoparticles i) Color change from the original solution after synthesis of AuNPs (0).
Figure 2. XRD patterns of Au nanoparticles, a) 10 min, b) 30 min.
Number of Particles
d = 14 nm (10 min)
70 60 50 40 30 20 10 0 0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45
Particle size (nm)
Figure 3. TEM (a), (b) TED, (c) HRTEM images of Au particles (10 min).
Number of Particles
80
d = 22 nm (30 min)
70 60 50 40 30 20 10 0 0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45
Particle size (nm)
Figure 4. TEM (a), (b) TED, (c) HRTEM images of Au particles (30 min).
Highlights
A new method of synthesis of gold nanoparticles at low temperatura.
The extracts of the xerophytic plant can reduce Au(III) to Au (0) in a few minutes
The NPsAu showed high stability with potential for biological applications.
Absorbance (u.a.)
a) Agave extract b) 1 min c) 2 min d) 3 min e) 4 min f) 5 min g) 10 min h) 30 min
h g f e d c a b 400
450
500
550
600
Wavelength (nm)
650
700
S0167-577X(18)31511-8 https://doi.org/10.1016/j.matlet.2018.09.122 MLBLUE 24990
To appear in:
Materials Letters
Received Date: Accepted Date:
13 November 2017 21 September 2018
Please cite this article as: F.B. Moreno-Luna, A. Tovar-Corona, J.L. Herrera-Perez, J. Santoyo-Salazar, E. RubioRosas, O. Vázquez-Cuchillo, Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts, Materials Letters (2018), doi: https://doi.org/10.1016/j.matlet.2018.09.122
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Quick synthesis of gold nanoparticles at low temperature, by using Agave potatorum extracts
F.B. Moreno-Luna1, A. Tovar-Corona2, J. L. Herrera-Perez1, J. Santoyo-Salazar3, E. RubioRosas4, O. Vázquez-Cuchillo5 *. 1 Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas, IPN. Av. Instituto Politécnico Nacional, 2580. Barrio Laguna Ticomán, C.P. 07340, CDMEX, México. 2 Universidad Politécnica Metropolitana de Puebla. Ingeniería en Biotecnología. Popocatépetl S/N, Tres Cerritos, C.P 72480, Puebla, México. 3 Departamento de Física CINVESTAV-IPN Apartado postal 14-740, C.P. 07360, CDMEX, México. 4 Benemérita Universidad Autónoma de Puebla, Facultad de Ingeniería Química, Avenida San Claudio y 18 Sur, C.P. 72570 Puebla, Puebla, México. 5 Instituto Tecnológico de Puebla, Departamento de Ciencias Básicas. Av. Tecnológico #420 Col. Maravillas, C.P. 72220, Puebla, México.
*Corresponding autor: [email protected]
Abstract: Gold nanoparticles were synthetized in short time by a novel and easy method by using an aqueous extract from Agave potatorum. The UV-Vis data show a characteristic band at 540 nm, from the minute 2 of synthesis that intensifies through the reaction time advances, by XRay diffraction and Selective Area Electronic Diffraction patterns, it is demonstrated the polycrystallinity of the samples, exhibiting the specific features of metallic gold; the Transmission Electronic Microscopy results show pseudospherical nanoparticles with an average size of 14 nm corresponding to the synthesized samples at 10 min and 22 nm in the case of the synthesized samples at 20 min. The results suggest that the Agave extract works also as stabilizer.
Keywords: Nanoparticles Au (0), Agave potatorum; Quick biosynthesis; Colloidal metal particles.
I.
Introduction
In the last decade, the development of new technologies to synthesize nanomaterials [1] have been addressed towards the objective of magnifying its properties in order; to be employed in multiple fields [2]. For instance, in the case of medicine area it is required to obtain nanomaterials possessing a strong affinity between the synthesized nanoparticles and the patient tissues, allowing to increase the effect that is wanted to be strengthen [3, 4], something very important that does not occur employing the current synthesis routes, mainly due to the toxic residues that remain attached to the nanoparticles surface [5]. Therefore, to
obtain better and more efficient results in biological applications it is needed the development of new techniques that allow those “biological-friendly” properties. Consequently, in recent years new nanoparticles synthesis methods have been developed, by using biotechnological procedures, employing microorganisms [6] and reductants from biological sources [7,8] which main purpose is to avoid the formation of the toxic substances that trigger rejection. Hence in the present study, it has been scouted the biosynthesis of gold nanoparticles (BioAuNP’s) by using a new methodology, that employs selective extracts obtained from Agave potatorum biomass, the nanoparticles are synthesized in short times and low temperature, with high stability and a big potential to be employed in biological applications.
II.
Materials and methods
a. Agave potatorum extract preparation In order to prepare the aqueous extract, 100 g of basal leaves from seven years old Agave potatorum plants were cut from cultivated specimens. The germplasm used to grow the plants was obtained from Tepanco de López, Puebla (N 18°30’41.476”, O 97°34’33.711”). The leaves used were carefully washed, sliced in small pieces and then macerated, the resultant liquid was filtrated with Whatman paper No.1, finally it was maintained at 4°C in the fridge. b. Biogenic AuNP’s synthesis Biogenic gold nanoparticles synthesis was performed by mixing 0.5 ml of extract with 9.5 ml of 1.0 mM HAuCl4 (Sigma-Aldrich 99.9%) solution. The resulting mixture was heated under reflux at 60°C, sampling aliquots from the minute 1 to 30. The obtained BioAuNP’s were maintained in darkness and refrigeration at 4 °C until use.
c. Characterization. UV-Vis spectra were recorded on a Perkin-Elmer lambda 35. The AuNP’s morphology, Transmission Electronic Microscopy (TEM) analysis, High Resolution TEM and the Selected Area Electronic Diffraction (SAED) pattern were obtained from JEOL, JEM-2010 microscope operated at 200 kV. To achieve the analysis, a drop of the samples was deposited in TEM copper grids carbon covered, letting it to evaporate at room temperature. The X ray diffraction (XRD) analysis were performed in a D8 Bruker Discover Series 2 diffractometer with Cu Kα radiation.
III.
Results and discussion
In Figure 1 (b-h), the UV-Vis spectra obtained during the first 30 minutes of synthesis are shown, observing from minute 2 the characteristic band at AuNPs near 540 nm, which is intensified by increasing the reaction time [9], this increase is related to the spread in size due to the nucleation process of the AuNPs [10]; The spectrum shows the characteristic signals of the agave extract used as a reductant during the synthesis and does not present any signal close to the characteristic band of the superficial plasmon of the AuNP’s. Evidence of the reduction of Au+ to Au0 ions was shown by changing the coloration of Chloroauric acid solution (HAuCl4) by turning from light yellow to violet (Figure inserted), initiating this change in approximately 2 minutes, which indicates the rapid reduction of Au + ions to their elemental metallic form, with their subsequent aggregation to form gold nanoparticles (AuNP´s). This reduction of Au ions is probably carried out by the large amount of organic matter with reducing characteristics such as saponins and terpenoids present in the Agave potatorum solution [11-13]. The XRD analyzes of the AuNPs sample synthesized at 10 min
are shown in Figure 2a, observing only reflections at 38.20 °, 44.40 °, 64.60 °, 77.60 ° and 81.76 °, such reflections are indexed to planes (111), (200), (220), (311) and (222) of the cubic structure centered on the faces (FCC) of the metal Au (JCPDS 001-2616). Similar reflections are observed for the sample synthesized for 30 min (figure 2b), In both diffractograms no characteristic signals were detected to gold oxide. Figure 3 shows the TEM images of the nanoparticles synthesized at 60 ° C for 10 min. observing a pseudospherical morphology, with an average diameter of 14 nm (inserted). However, the materials obtained at 30 minutes (at the same temperature of 60 ° C) are shown in Figure 4 with an average size of 22 nm (inserted). The interplanar distance of the samples synthesized at 10 and 30 minutes are shown in Figure 3b and 4b, which is close to 0.233 nm corresponding to the distance from the plane (111) of gold (0). This result joined to the electron diffraction patterns (TED) (Figure 3c and 4c) confirms the high crystallinity of the AuNPs obtained by this synthetic route. The pseudospherical form of the AuNP’s may be due to the presence of organic compounds that perform the surfactant function [14], such as the present saponins in the used extract, this situation can be confirmed in the future with other studies.
IV.
Conclusions
A method of biosynthesis of Au nanoparticles using extracts of the xerophytic plant, Agave potatorum, was developed, obtaining the nanomaterials in short times and low temperature (60 °C) of synthesis. The TEM results showed that pseudospherical Au nanoparticles having a size of 14 nm were obtained at 10 minutes of reaction, this size is increased to 22 nm after 30 min of reaction. By UV-Vis spectroscopy, it was shown that the reduction starts from minute 2 of the reaction, evidenced by the band at 540 nm that increases with the time of
synthesis. The results by HRTEM, XRD and TED show that the AuNPs are in the cubic phase centered on the faces (fcc) of Au (0). The reductant developed a stabilizer-surfactant functionality, allowing to modify the size of the synthesized AuNP´s to change the synthesis time.
V.
Acknowledgements
This research was supported by the projects PRODEP DSA/103.5/15/7495, TecMEX 5833.16-P, PRODEP IDCA 23898, SECITI-CDMX México (Grant No. 071-2016), SEPIUPIITA (SIP 20162015)
Bibliography. [1]
Hasan S., (2015) A Review on Nanoparticles: Their Synthesis and Types. Research Journal of Recent Sciences. Vol. 4, 1-3.
[2]
Heera, P., & Shanmugam, S. (2015) Nanoparticle characterization and application: an overview. Int.J.Curr.Microbiol.App.Sci. 4(8), 379-386.
[3]
Wang E., Wang A., (2014) Nanoparticles and their applications in cell and molecular biology. Integr. Biol. 6, 9-26.
[4]
Min J., Bee E., Seop M., Bae B., Jung T., (2015) Self-assembly of biogenic gold nanoparticles and their use to enhance drug delivery into cells. Colloids and Surfaces B: Biointerfaces. Volume 135 (1), 27-34.
[5]
Sharma D. et al., (2015) Biogenic synthesis of nanoparticles: A review. Arabian Journal of Chemistry. http://dx.doi.org/10.1016/j. arabjc.2015.11.002
[6]
Kitching M., Ramani M & Marsili E. (2014) Fungal biosynthesis of gold nanoparticles: mechanism and scale up. Microbial Biotechnology 8, 904-917.
[7]
Mittal A. K., Chisti Y., Banerjee U. C. (2013) Synthesis of metallic nanoparticles using plant extracts. Biotechnol Adv. 31(2), 346–356.
[8]
A. Tovar-Corona, M.A. Lobo-Sánchez, J.L. Herrera-Perez, R. Zanella, J.I. RodriguezMora, O. Vázquez-Cuchillo, (2018) Green synthesis of copper (0) nanoparticles with cyanidine-O-3-glucoside and its strong antimicrobial activity. Materials Letters 211 (2018) 266–269.
[9]
Britto R., Cortez M., Ramírez L., Larios E., Alvarez R., Rocha O., Delgado Y., Nuñez C., Arizpe H., Hernández A., Flores M., (2016) Instant synthesis of gold nanoparticles at room temperature and SERS applications. Physics Letters A, 380(34), 2658-2663.
[10]
Haiss W., Thanh N. T. K., Aveyard J. & Ferning D. G. (2007) Determination of size and concentration of Gold nanoparticles from UV-Vis spectra. Analytical Chemistry, 79(11) 4215-4221.
[11]
Rizwan K., Zubair M., Rasool N., Riaz M., Zia-Ul-Haq M., De Feo V. (2012) Phytochemical and Biological Studies of Agave attenuata. International Journal of Molecular Sciences, 13, 6440-6451.
[12]
Santos H.J.L., (2008), Identificación y cuantificación de terpenos en Agave mezcalero por microextracción, en fase scci, (2008), Facultad de Química UNAM
[13]
Sidana J., Singh B., Sharma O. P., (2016), Saponins of Agave. Chemistry and bioactivity, Phytochemistry, 160, 22-46.
[14]
Gonzalez L., Almaraz N., Proal J., Robles F., Del Toro G., Quintos M., (2013) Surfactant properties of the saponins of Agave Durangensis, application on arsenic removal. International Journal of Engineering and Applied Sciences, 4(2), 87-94.
Absorbance (u.a.)
FIGURES.
a) Agave extract b) 1 min c) 2 min d) 3 min e) 4 min f) 5 min g) 10 min h) 30 min
h g f e d c a b 400
450
500
550
600
650
700
Wavelength (nm) Figure 1. The typical UV–vis spectra a) Agave extract. b-h) Gold nanoparticles i) Color change from the original solution after synthesis of AuNPs (0).
Figure 2. XRD patterns of Au nanoparticles, a) 10 min, b) 30 min.
Number of Particles
d = 14 nm (10 min)
70 60 50 40 30 20 10 0 0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45
Particle size (nm)
Figure 3. TEM (a), (b) TED, (c) HRTEM images of Au particles (10 min).
Number of Particles
80
d = 22 nm (30 min)
70 60 50 40 30 20 10 0 0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45
Particle size (nm)
Figure 4. TEM (a), (b) TED, (c) HRTEM images of Au particles (30 min).
Highlights
A new method of synthesis of gold nanoparticles at low temperatura.
The extracts of the xerophytic plant can reduce Au(III) to Au (0) in a few minutes
The NPsAu showed high stability with potential for biological applications.
Absorbance (u.a.)
a) Agave extract b) 1 min c) 2 min d) 3 min e) 4 min f) 5 min g) 10 min h) 30 min
h g f e d c a b 400
450
500
550
600
Wavelength (nm)
650
700