Abstract
Development of biologically inspired experimental processes for the synthesis of nanoparticles is evolving into an important branch of nanotechnology. The present study deals with the synthesis of silver nanoparticles using Gliricidia sepium. On challenging, leaf broth of Gliricidia sepium and aqueous AgNO3 (1mM) solution changed from yellowish green to brown, the final color appeared gradually with time. The entire reaction mixture turned to brown color after 12 hrs of reaction, and exhibits an absorbance peak around 440 nm characteristic of Ag nanoparticle, its surface plasmon absorbance and due to different shapes of lone spherical or roughly spherical Ag nanoparticles. Transmission electron microscopy (TEM) analysis showed silver nanoparticles which are polydispersed and ranged in size from 10-50 nm with an average size of 27 nm, the particles were predominantly spherical. X-ray diffraction (XRD) studies reveals a number of Braggs reflections that may be indexed on the basis of the face centered cubic structure of silver nanoparticle and Fourier Transform Infrared Spectroscopy (FTIR) analysis, which showed that silver nanoparticles are capped. Phytosynthesized silver nanoparticles show the antibacterial activity against the Staphylococcus aureus ATCC 6538P, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Klebsiella pneumoniae (clinical isolate). The approach of phytosynthesis appears to be cost efficient eco-friendly and easy alternative to conventional methods of silver nanoparticles synthesis.
Keywords: Phytosynthesis, silver nanoparticle, Gliricidia sepium, antibacterial, TEM, FTIR, XRD