Bioreduction of chloroaurate ions to gold nanoparticles by culture filtrate of Pleurotus sapidus Quél

Abstract The present study demonstrates an eco-friendly, non-toxic and cost-effective protocol for synthesis of gold nanoparticles (AuNPs) in aqueous medium using Pleurotus sapidus culture filtrate as the reducing and stabilizing agent. On treating chloroauric acid solutions with fungal culture filtrate, rapid reduction of chloroaurate ions is observed leading to the formation of highly stable AuNPs in solution. The particles thereby obtained were characterized by different spectroscopic and X-ray analysis. EDX-spectrum revealed the presence of gold in the nanoparticles. FTIR spectroscopy confirmed the presence of a protein shell outside the nanoparticles which in turn also support their stabilization. DLS and TEM analysis of the AuNPs indicated that they ranged in size from 15 to 100 nm with average size of 65±5 nm. A probable mechanism behind the biosynthesis is discussed, which leads to the possibility of using the present protocol in future “nano-factories”.