Chapter 7 - Mycosynthesis of gold nanoparticles: mechanisms and applications

Abstract

The mycosynthesis approach for gold nanoparticle (AuNPs) synthesis has attracted considerable interest over other conventional physicochemical methods because this approach excludes the use of toxic chemicals. Naturally, fungi are cosmopolitans, high stress tolerates, and novel metal reductants. The fungal-mediated mycosynthesis of gold AuNPs could be the preferred choice as it has excellent biocompatibility and is economical, eco-friendly, and has easy downstream processing. They secrete a wide range of secondary metabolites, peptides, and proteins extracellularly that find applications in various research fields. Fungal extracellular metabolites and redox proteins can act as reducing/stabilizing agents in the formation of nanocrystals. Optimized extracellular conditions can also alter the size and shape of the synthesized AuNPs. Therefore, the extracellular approach could be an ideal method in the bulk productivity of AuNPs. A considerable number of researchers have reported on the synthesis of AuNPs by filamentous fungi and yeast, despite the reliability of the organisms. Protein- and polysaccharide-coated AuNPs have found prominent biomedical applications due to their oxidation resistance, multiple surface functionality, and stability. They are widely used particles that have many therapeutic applications like targeted drug delivery, cosmetics, biosensors, and allied areas. In this book chapter, we elaborate on the mycosynthesis of AuNPs, the mechanism behind the formation, and applications with the recent literature.