Rapid and green synthesis of metallic/bimetallic nanoparticles using aqueous plant extract of Triphala with their excellent bio-efficacies

Abstract

The synthesis of nanoparticles of variable sizes, shapes, chemical compositions and controlled dispersity and their potential use for human benefits are principally concerned with Nanotechnology. Although pure, well defined nanoparticles may be synthesized from the conventional chemical and physical methods, these methods are pretty expensive and critically dangerous to the environment. A wide range of microorganisms, plant extract or plant biomass can possibly be used as an alternative to chemical and physical methods for the fabrication of nanoparticles in an eco-friendly manner. Engaging plants in the synthesis of nanoparticles are evolving as beneficial in comparison to the microbes due to the presence of broad variability of bio-molecules in plants which may act as capping and reducing agents and thus increases the speed of reduction and stabilization of nanoparticles. Secondary plant metabolites (proteins, fatty acids, sugars, enzymes, phenolic, etc.) in the sources are intensely involved in both bio reduction of metallic ions to NPs and their stabilization. The biological methods opted for the synthesis of nanoparticles is safe, dynamic and energy efficient. NPs synthesized via biological methods are found to be more stable than others methods. Furthermore, functional groups i.e. polyols and carboxylic acid have also been alleged to be liable for the synthesis of NPs. Here we have reconnoitred an ingenious contribution for synthesis of silver, gold and bimetallic nanoparticles using fruit extract of the chosen medicinal plants. The procedure for the fabrication of stable AgNPs, AuNPs and Ag@AuNPs is rapid, simple and viable. Synthesized nanoparticles were characterized by various methods, viz. FESEM, TEM, XRD, EDX, DLS, UV–Vis and FTIR. Among various metal nanoparticles, AgNPs and AuNPs have several effective applications as antimicrobial, sensors and detectors besides their biomedical applications.