Green Synthesis of Nanomaterials Using Plant Extract: A Review

For the last two decades, extensive research is conducted on metal and metal oxide nanoparticles and their application in the field of medical, cosmetics, catalysts, packaging, photonics, agriculture and electronics. However, these nanoparticles show toxicity to the environmental, human and animal health. The toxicity effects of nanoparticles are mainly due to their size, which can easily pass through physiological barriers and also due to the synthesis procedure. The toxicity due to their size cannot be avoided, but toxicity due to the synthesis process can be nullified by adopting the biosynthesis process. Bacteria, fungus, fish scales, plant extracts and algae are used to synthesize metal and metal-oxide nanoparticles such as silver, gold, iron-oxide, zinc-oxide, zirconia, etc. For the last few years, researchers have been working on synthesis methods of plant extracts to produce stable, cost-effective and economical nanoparticles. In this review, we focus on the biosynthesis of nanoparticles using different parts of plant extracts. The review contains a summary of selected papers from 2018-20 with a detailed description of the process of synthesis, mechanism, characterization and their application in various fields of biosynthesized metal and metal oxide nanoparticles.