%0 Journal Article
%T Biosynthesis of Silver Nanoparticles from Desmodium triflorum: A Novel Approach Towards Weed Utilization
%A Naheed Ahmad
%A Seema Sharma
%A V. N. Singh
%A S. F. Shamsi
%A Anjum Fatma
%A B. R. Mehta
%J Biotechnology Research International
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/454090
%X A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag+ ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425£¿nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5¨C20£¿nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2¦È values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H+ ions along with NAD which acts as a strong redoxing agent; this seems to be responsible for the formation of AgNPs. Water-soluble antioxidative agents like ascorbic acids further seem to be responsible for the reduction of AgNPs. These AgNPs produced show good antimicrobial activity against common pathogens. 1. Introduction Nanoparticles with controlled size and composition are of fundamental and technological interest as they provide solutions to technological and environmental challenges in the areas of solar energy conversion, catalysis, medicine, and water treatment. Thus, production and application of nanomaterials from 1 to 100 nanometers (nm) is an emerging field of research [1, 2]. Global warming and climate change have induced a worldwide awareness and effort to reduce generated hazardous wastes. Thus, ¡°Green¡± chemistry and chemical processes are progressively being integrated in science and industry for sustainable development [3]. Nanomaterials due to their sheer size show unique and considerably changed physical, chemical, and biological properties compared to their macro scale counterparts [4]. Gold, silver, and copper have been used mostly for the synthesis of stable dispersions of nanoparticles, which are useful in areas of photography, catalysis, biological labeling, photonics, optoelectronics, and surface-enhanced Raman scattering (SERS) detection [5¨C7]. Biological methods are considered safe and ecologically sound for the nanomaterial fabrication as an alternative to conventional physical and chemical methods. Biological routes to the synthesis of these particles have been proposed by exploiting microorganisms [8¨C12] and by vascular plants [13¨C22]. The functions of these materials depend on their composition and structure. Plants have been reported to be used
%U http://www.hindawi.com/journals/btri/2011/454090/