Biosynthesis of Silver nanoparticles using root extract of the medicinal plant Justicia adhatoda: Characterization, electrochemical behavior and applications

A facile and green approach has been developed to synthesize silver nanoparticle (Ag-NPs). This was carried out by a biosynthetic route using Justicia Adhatoda root extract as reducing and stabilizing agent. The structure, composition, average particle size (~25 nm) and surface morphology of Ag-NPs were characterized by the X-ray diffraction, transmission electron microscope and atomic force microscope analyses. The possible functional groups in the plant extracts were identified by FT-IR analysis. Electrochemical property of the AgNPs was analysed by cyclic voltammetry that displayed an oxidation peak potential at Epa = 0.438 V. Mechanism of the formation of Ag-NPs was proposed which showed that the phenolic compounds of the root extract respond for the reduction of silver ions to silver nanoparticles. Ag-NPs exhibit good antioxidant and antibacterial activities. This biosynthetic approach could open a path for environmentally friendly, simple, cost effective, alternate for conventional synthesis. This prevented hazardous chemicals and was useful for applications in medicine and large scale production of metallic nanoparticles.