Chapter 19 - Green synthesis of metal nanoparticles and its antibacterial study

Abstract

The primary focus of this chapter is to illustrate the recent advances made in the field of nanoscience and nanotechnology. Specifically, this chapter includes the synthesis of metal nanoparticles (MNPs) by bioroute or green route and this method of synthesis is called green synthesis. The process of green synthesis for the preparation of MNPs is a bio-friendly and economical one. In green synthesis, MNPs are synthesized mainly from different parts of green plants like leaves, flowers, fruit, seed, root, bark, etc. The general metallic salts used for the synthesis of MNPs are gold (Au), silver (Ag), platinum (Pt), copper (Cu), etc. By different scientific studies since prehistoric times, it is confirmed that green plants are gifted naturally with several phytochemicals such as vitamins, sterols, terpenes, polyphenols, carotenoids, etc., with several beneficial effects. Out of several beneficial effects, one is their reducing property by which it reduces metallic salts to their corresponding MNPs. These phytochemicals are responsible for the preparation and also for the stabilization of the MNPs. The phytochemicals present in plant extract acts as capping agent by restricting the synthesized MNPs to agglomorate to less reactive big sized nano particles. The prepared MNPs are characterized and confirmed by UV-Vis, FTIR, SEM, TEM, XRD, DLS, EDAX, and zeta-potential analysis. The synthesized MNPs have significant diverse medicinal potential including antibacterial, antiviral, antifungal, anticancer, antidiabetic, antiinflammatory, and antioxidant properties. In this chapter, a brief study of antimicrobial activity against several pathogens is also highlighted.