Eco-friendly synthesis of silver nanoparticles using leaf extract of Grewia flaviscences and study of their antimicrobial activity

In this work, we report the eco-friendly synthesis of silver nanoparticles (AgNPs) by bio-reduction method. Aqueous extract of Grewia flaviscences plant leaf was used as stabilizing and reducing agent. Formation of AgNPs was initially identified by change in color from light yellow to dark brown. UV-visible spectra showed the characteristic surface Plasmon resonance peak of synthesized AgNPs between 380 and 460 nm. X-ray diffraction analysis revealed the crystalline nature of AgNPs, whereas Energy-dispersive X-ray spectroscopy confirms the metallic nature of silver. Field emission scanning electron microscopy and transmission electron microscopy images showed the spherical nature of the particles whereas size distribution was measured by Zetasizer, which revealed that size of AgNPs were in the range of 50-70 nm. Biosynthesized AgNPs exhibited antimicrobial activity against both gram positive and gram negative bacteria, Bacillus and Pseudomonas aeruginosa. Sps., respectively. The effects of leaf extract and silver nitrate concentrations on AgNPs have also been studied. (C) 2015 Elsevier B.V. All rights reserved.