Biological Synthesis of Metallic Nanoparticles by Bacteria, Fungi and Plants

Over the past few decades interest in metallic nanoparticles and their synthesis has greatly increased. This has resulted in the development of numerous ways of producing metallic nanoparticles using chemical and physical methods. However, drawbacks such as the involvement of toxic chemicals and the high-energy requirements of production make it difficult for them to be widely implemented. An alternative way of synthesising metallic nanoparticles is by using living organisms such as bacteria, fungi and plants. This "green" method of biological nanoparticle production is a promising approach that allows synthesis in aqueous conditions, with low energy requirements and low-costs. This review gives an overview of some of these environmentally friendly methods of biological metallic nanoparticle synthesis. It also highlights the potential importance of these methods in assessing nanoparticle risk to both health and the environment.