Biological Synthesis and Antibacterial Activityof Silver and Gold Nanoparticles Produced by the fungus Aspergillus terreus

"Abstract In this study, we investigated the fungus Aspergillus terreus used for the biosynthesis of silver and gold nanoparticles. The cell free filtrate of Aspergillus terreus reacted with AgNo3 and HAuCl4 ions separately, resulting formation of silver and gold nanoparticles. The silver and gold nanoparticles were characterized by Visual analysis, UV-Vis absorption spectroscopy and Transmission electron microscopy (TEM). The silver and gold nanoparticles exhibited maximum absorbance at 430 and 540 nm in UV-Vis spectroscopy. TEM micrograph showed polydisperse spherical and ellipsoid nanoparticles in the size range from 1-50 nm. Aspergillus terreus synthesized silver nanoparticles found strong antibacterial activity against Staphylococcus aureus and Shigella sps. However gold nanoparticles do not showed any antibacterial activity. Biological approach using the fungi is a novel way towards the safe, cost effective and ecofriendly method for the synthesis of gold nanoparticles is gaining importance in the field of nanotechnology. "