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

Gitanjali B. Shelar, Ashok M. Chavan

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.

Keywords: Aspergillus terreus, UV-Vis absorption spectroscopy, Transmission electron microscopy TEM, antibacterial activity, Staphylococcus aureus, Shigella sps