Enzymatic Formation of Gold Nanoparticles Using <i>Phanerochaete Chrysosporium</i>

When fungus Phanerochaete chrysosporium was challenged with gold ions under ambient aqueous conditions gold nanoparticles were formed within 90 minutes. Controlling experimental conditions like the age of fungus, incubation temperature and different concentration of gold chloride solution had drastic effect on the morphology of the nanoparticles formed. The enzyme assays indicated the role of enzyme as a reducing and shape directing agent. Laccase was the dominating enzyme in the case of fungal media for the synthesis of extracellular gold nanoparticles. Ligninase was responsible for the intracellular formation of nanoparticles on the fungal mycelium. The stabilization of the nanoparticles (NPs) via protein layer was evident by Atomic Force Microscopy (AFM) which revealed the nanoparticles to be spherical in the range of 10-100 nm. This study represents an important advancement in the use of fungal enzymes for the biosynthesis of highly stable gold nanoparticles by a green and mild technique in one pot in aqueous media.