Synthesis of Silver Nanoparticles by Microbial Method and Their Characterization

The silver nanoparticles are synthesized by using microbial reduction of silver ions in the presence of fungus Aspergillus flavus . The fungus , Aspergillus flavus when challenged with silver nitrate solution accumulated silver nanoparticles on the surface of its cell wall in 96 hr . The silver nanoparticles synthesized are characterized by using UV-spectroscopy. An absorption peak at 420 nm in UV-visible spectrum corresponds to the Plasmon resonance of silver nanoparticles. The presence of protein as a stabilizing agent which surrounds the nanoparticles was confirmed by FTIR spectroscopy. The structural properties of silver nanoparticles were confirmed using XRD technique. The surface morphology of silver nanoparticles was studied using SEM. From SEM images grain size of silver nanoparticles is determined up to nano level.