Biogenic Gold Nanoparticles: Current Applications and Future Prospects

Metal nanoparticles have gained considerable attention as versatile nanomaterials due to their size- and shape- dependent electrical, electronic, optical, and catalytic properties. Various physical and chemical approaches have been investigated for synthesizing metal nanoparticles, specifically gold nanoparticles due to their biocompatibility, antioxidant potentials, catalytic activity, and other promising characteristics. As the chemical based approaches have led to questions on toxicity, plant-based sources and microorganisms like bacteria, fungi and algae have been evaluated for synthesizing metal nanoparticles. Gold nanoparticles derived from biological sources are expected to have different properties than those derived from chemical sources, allowing for a wider range of applications. This review provides an overview of the myriad of sources explored for the synthesis of gold nanoparticles which have found useful applications in several fields. The general approach for synthesizing gold nanoparticles is provided followed by the major applications in specific fields namely medicine, biology, electrochemistry and catalysis. Additionally, the possible challenges and future prospects of biosynthesis of nanoparticles have been highlighted. This work could provide an update on the recent advances in the applications of biogenic nanoparticles for future developments.