Development of biologically inspired experimental processes for the synthesis of nanoparticles is evolving into an important branch of nanotechnology. The bioreduction behaviour of various plant leafextracts such as Helianthus annus (Asteraceae), Basella alba (Basellaceae), Oryza sativa, Saccharum officinarum, Sorghum bicolour and Zea mays (Poaceae) in the synthesis of silver nanoparticles wasinvestigated employing UV/Visible spectrophotometry, XRD (X-ray diffraction) and SEM (Scanning Electron Microscopy). H. annus was found to exhibit strong potential for rapid reduction of silver ions. It was observed that there is no correlation always between the colour development and the increase in absorbance exhibited by the nanometal synthesised. The work adds to the confirmation of previous reports on biosynthesis of nanometals using plant leaf extracts

Leela, A

Vivekanandan, M

English

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 African Journal of Biotechnology Vol. 7 (17), pp. 3162-3165, 3 September, 2008     Available online at http://www.academicjournals.org/AJB ISSN 1684–5315 © 2008 Academic Journals       Full Length Research Paper  Tapping the unexploited plant resources for the synthesis of silver nanoparticles  Arangasamy Leela1* and Munusamy Vivekanandan2  1Department of Biotechnology, Bharathidasan University, Tiruchirappalli-620024. TN. India. 2Biosciences and Research, Vivekananda Institutions, Elayampalayam, Thiruchengode-637 205. TN, India.  Accepted 28 July, 2008  Development of biologically inspired experimental processes for the synthesis of nanoparticles is evolving into an important branch of nanotechnology. The bioreduction behaviour of various plant leaf extracts such as Helianthus annus (Asteraceae), Basella alba (Basellaceae),  Oryza sativa, Saccharum officinarum, Sorghum bicolour and Zea mays (Poaceae) in the synthesis of silver nanoparticles was investigated employing UV/Visible spectrophotometry, XRD (X-ray diffraction) and SEM (Scanning Electron Microscopy). H. annus was found to exhibit strong potential for rapid reduction of silver ions. It was observed that there is no correlation always between the colour development and the increase in absorbance exhibited by the nanometal synthesised. The work adds to the confirmation of previous reports on biosynthesis of nanometals using plant leaf extracts.   Key words: Nanoparticles bioreduction, nanometals, Helianthus annus, X-ray diffraction.   INTRODUCTION  Nanoparticles are being viewed as fundamental building blocks of nanotechnology. The most important and dis-tinct property of nanoparticles is that they exhibit larger surface area to volume ratio. The most effectively studied nanoparticles today are those made from noble metals, in particular Ag, Pt, Au and Pd. Metal nanoparticles have tremendous applications in the area of catalysis, opto-electronics, diagnostic biological probes and display devices. Among the above four, silver nanoparticles play a significant role in the field of biology and medicine. The aforesaid metal nanoparticles have been synthe-sized using a variety of methods, including hard-template (Zhou et al., 1999), bio-reduction (Canizal et al., 2001; Mouxing et al., 2006) and solution phase syntheses (Sun et al., 2003; Yu et al., 1997). In the synthesis and assem-bly strategies of nanoparticles and nanomaterials, precursors from liquids, solids or gas phase are used employing chemical and physical deposition approach. The manufacturing techniques fall under  two  categories:    *Corresponding author. E-mail: tomsleela@gmail.com. ‘bottom-up’ and ‘top-down’ approach. The bottom-up approach promises a better chance to obtain nanostructures with less defects, more homogenous chemical composition and better short and long range ordering, because this approach is mainly driven by the reduction of Gibb’s free energy. Among the various methods like sol-process, micelle, sol-gel process, chemical precipitation, hydrothermal method, pyrolysis, chemical vapour deposition, bio-based protocol etc., bio-based protocol is the most important and eco-friendly production method.  Biosynthesis of nanoparticles by plant extracts is currently under exploitation. The use of Azadirachta indica (Neem) (Shankar et al., 2004), Medicago sativa (Alfalfa) (Gardea – Torresday et al., 2003), Aloe vera (Chandran et al., 2006), Emblica officinalis (amla, Indian Gooseberry) (Amkamwar et al., 2005), and micro-organisms (Duran et al., 2005; Vigneshwaran et al., 2006; Bhainsa and D’souza, 2006) has already been reported. According to previous reports, the polyol com-ponents and the water-soluble heterocyclic components are mainly responsible for the reduction of silver ions and the stabilization of the nanoparticles,  respectively.  There  Arangasamy and Munusamy        3163    00.511.522.53251269287305323341359377395413431449467485500Wavelength (nm)Absorbance (OD)Silvernitrate alone Oryza sativa Zea maysSorghum bicolor Saccharum officinalis Basella albaHelianthus annus  Figure 1. UV visible absorption spectra recorded as a function of time of reaction at 10-3 M aqueous solution of silver nitrate with different leaf extracts. The silver nanoparticle formation was monitored through UV-Visible absorption spectroscopy (excitation band near 430 nm for silver) at regular intervals as a function of time of reaction on a Genesys 10-UV Thermo Spectrophotometer operated at a resolution of 3 nm.    are also reports on reductases (Anil Kumar et al., 2007) and polysaccharides (Huang and Yang, 2004) as factors involved in biosynthesis and stabilization of the nano-particles, respectively. Our hypothesis is that several factors together determines the nanoparticle synthesis, including the plant source, the organic compounds in the crude leaf extract, the concentration of silver nitrate, the temperature and other than these, even the pigments in the leaf extract. The longtime aim is to identify those compounds and the mechanism in detail. As a prelimi-nary work we screened the following plants:  Basella alba (Basellaceae), Helianthus annus, (Asteraceae), Oryza sativa, Saccharum officinarum, Sorghum bicolour and Zea mays (Poaceae) and systematic comparative study was carried out to investigate their efficiency to reduce silver ions as well as the formation of silver nanoparticles.   RESULTS AND DISCUSSION  Nanotechnology is a fast emerging discipline not only in physics and chemistry but also in the field of biology. In view of the tremendous applications of nanotechnology, there is a fillip among scientists to carry out research in this most vital discipline. Chemists are highly interested in synthesizing nanoparticles of different dimensions employing many of the precious metals. Already scientists have started exploiting the bio-based synthesis of nano-metals using leaf extracts and microorganisms (bacteria and fungi). The present study was conducted to screen the un-exploited plant sources in the development of silver nanoparticles. The plants belonging to the following families such as Basellaceae, Asteraceae, and Poaceae were selected and their rates of reduction of silver nitrate was investigated. The silver nanoparticle formation was confirmed by X-ray diffraction (XRD) and electron micro-scopy. The qualitative analysis for nitrate reduction and the antimicrobial activity of the silver the synthesized nanoparticle was also performed. The absorption spectrum of aqueous silver nitrate only solution exhibited  max at about 220 nm. There was a gradual increase in color development in the reaction mixture (silver nitrate solution + plant leaf extract). Of all the plants studied, the intensity of color development in the reaction mixture was significantly higher in H. annus (sunflower), B. alba (spinach) and S. officinarum (sugarcane). In the spectrophotometric analysis (Figure 1), though the reaction mixture of each plant studied exhibited a strong absorption between 400 and 500 nm, sunflower was found to exhibit very strong absorption. Also it was observed that there is no correlation always between  the   3164         Afr. J. Biotechnol.    Position [°2Theta]30 40 50 60 70 80 90Counts050100 Maruthamuthu_21                     Pos. [°2Th.] Height [cts] FWHM [°2Th.] d-spacing [Å] Rel. Int. [%] 32.3068 95.08 0.3178 2.77106 100.00 5.0227 5.87 0.4896 2.01193 6.18   Figure 2. The XRD Image of silver nanoparticles synthesised using Sunflower leaf extract. The diffraction patterns were obtained by measurement of angles at which X-ray beam is diffracted by the crystalline phases in the specimen. X-ray diffraction (XRD) measurement of the bio-reduced silver nitrate solution drop-coated on glass substrate bio-film was carried out on a Philips PW 1830 instrument operating at 40 kV and a current of 30 mA with Cu Ka radiation.      Figure 3. The SEM image (WD 7.7 mm 25.0 kV x 40 k) of silver nanoparticles synthesised using sunflower leaf extract. Dried suspension of silver nanoparticles synthesized by reduction of silver ions in water was subjected to electron microscopy (SEM) using Hitachi made Scanning Electron Microscope of Model No.S3000H at central electro chemical research institute colour development and the increase in absorbance exhibited by the nanometal synthesised. The difference in the morphology of the nanoparticle synthesised may be the possible reason for the difference in optical properties (Xu and Kall, 2002). The biosynthesised silver nanostructure by employing sunflower leaf extract was further demonstrated and con-firmed by the characteristic peaks observed in the XRD image (Figure 2) and the structural view under the scanning electron microscope (Figure 3). Thus the sunflower leaf extract was found to be promising in the development of silver nanoparticles. The SEM image showing the high density silver nanoparticles synthesized by the sunflower leaf extract further confirm-ed the development of silver nanostructures by the plant extract.  Isolation and testing of individual fractions for metal ion reduction and binding with the nanoparticles is neces-sary. By altering the pH, strength of elements, plant sources, and incubation temperature of the nanoparticle synthesis reaction mixture, the synthesis methods, it is possible to create a wide range of different nanoparticles.       Nanoparticles of various sizes and properties may be obtained by further tapping the plant bioresources of different kind in wild environment.    ACKNOWLEDGEMENTS  Sincere thanks to the Director, Central Electro Chemical Research Institute for the analytical facilities. Also heartfelt thanks to Dr. Parthasarathy, Department of Physics, BARD, for his valuable suggestions.  REFERENCES  Anil Kumar S,  Abyaneh MK,  Gosavi SW,  Kulkarni SK,  Pasricha R, Ahmad A, MI Khan (2007). Nitrate reductase-mediated synthesis of silver nanoparticles from AgNO3. Biotechnol. Lett. 29(3): 439-444. Amkamwar B, Damle C, Ahmad A, Sastry M (2005). Biosynthesis of gold and silver nanoparticles using Emblica officinalis fruit extract, their phase transfer and transmetallation in an organic solution. J. Nanosci. Nanotechnol. 5(10): 1665-1671. Bhainsa KC, D'Souza SF (2006). Extracellular biosynthesis of silver nanoparticles using the fungus Aspergillus fumigatus. Colloids Surf B Biointerfaces. 47(2,1): 160-164 Canizal G, Ascencio JA, Gardea-Torresday J, Jose-Yacaman M (2001). Multiple twinned gold nanorods grown by bio-reduction techniques. J. Nanoparticle Res. 3: 475-481. Chandran SP,  Chaudhary M, Pasricha R,  Ahmad A,  Sastry M (2000). Synthesis of Gold Department of Biotechnology, Bharathidasan University, Tiruchirappalli-620024. TN. India. Nanotriangles and Silver Nanoparticles Using Aloe vera Plant Extract. Biotechnol. Prog 22: 577-583. Duran N, Marcato PD, Alves OL, Souza GI, Esposito E (2005). Mechanistic aspects of biosynthesis of silver nanoparticles by several Fusarium oxysporum strains. J. Nanobiotechnol. 3: 8.                          Arangasamy and Munusamy        3165    Huang H, Yang X (2004). Synthesis of polysaccharide-stabilized gold and silver nanoparticles: a green method. Carbohydr. Res. 339: 2627-2633.  Mouxing F, Qingbiao L, Daohua S, Yinghua L, Ning H, Xu D, Huixuan W, Jiale H (2006). Rapid Preparation Process of Silver Nanoparticles by Bioreduction and Their Characterizations. Chin. J. Chem. Eng. 14(1): 114-117. Shankar SS,  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: 496-502. Sun Y, Mayers B, Herricks T, Xia Y (2003). Polyol Synthesis of Uniform Silver Nanowires: A Plausible Growth Mechanism and the Supporting Evidence. Nano Lett. pp: 955-960. Xu H,  Käll M (2002). Morphology effects on the optical properties of silver nanoparticles. J. Nanosci.  Nanotechnol. 4: 254-259.  Yu YY, Chang SS, Lee CL, Wang CRC (1997). Gold nanorods: electrochemical synthesis and optical properties. J. Phys. Chem. Biotecnol. 101: 6661-6664.  Zhou Y, Yu SH, Cui XP, Wang CY, Chen ZY (1999). Formation of Silver Nanowires by a Novel Solid- Liquid Phase Arc Discharge Method. Chem. Mater. 11: 545-546.                                  

Tapping the unexploited plant resources for the synthesis of silver nanoparticles

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Tapping the unexploited plant resources for the synthesis of silver nanoparticles

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