Bioinspired Metal Nanoparticles with Special Reference to Mechanism

Abstract

The interest in metallic nanoparticles and their synthesis has greatly increased over the past decades. Several physical and chemical methods for synthesis of nanoparticles have been developed. However, involvement of toxic chemicals, high-energy consumption, and costly equipments are the drawbacks to their wide use. Therefore, “green” approach for the synthesis of metallic nanoparticles by using plants and their extracts, algae, fungi, and bacteria, including actinomycetes as well as viruses and biomolecules, is promising way, which is quick, low-cost, and eco-friendly. The mechanism of synthesis of metal nanoparticles by living organisms has not been fully explained, to date. However, the bioreduction process with involvement of NADP-dependent nitrate reductase is considered as a main step. The physical (e.g., morphology, zeta potential) and chemical (composition of capping agents) properties of nanoparticles, which effect on their activity, can be controlled during biosynthesis process. There are several factors such as temperature, time, pH, and concentration of reagents used, which influence the biological synthesis of metallic nanoparticles, mainly the size and yield of synthesized nanoparticles.