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

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”.

The change of colours signature the formation of gold nanoparticles and the electron microscopic image showed the different types of gold nanoparticles.Figure optionsDownload as PowerPoint slideHighlights
► This is the process to biosynthesize of gold nanoparticles by using a mushroom.
► A time dependent colour change to dark red signifies the synthesis of nano-gold.
► The synthesis of the gold nanoparticles was monitored by UV–visible spectroscopy.
► Synthesized gold nanoparticles were characterized by DLS, XRD, EDX, FTIR and TEM.