ECO-FRIENDLY SYNTHESIS OF SILVER NANOPARTICLES USING CALOTROPIS GIGANTEA LEAF EXTRACT: STRUCTURAL CHARACTERIZATION AND EVALUATION OF ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES

Abstract

Nanoparticles are unique small-scale particles compared to their large bulk counterparts. Calotropis gigantea is widely used in traditional medicine. Plant extract contains micronutrients, which acts as a reducing factor when synthesized with metal nanoparticles. The study provides eco-friendly synthesis of silver nanoparticles using Calotropis gigantea leaf extract and their biological potential. The investigation involves various characterization techniques: resultant AgNPs were confirmed by UV-Vis spectroscopy at 390 nm and XRD analysis with crystalline nature and equivalent particle size of 30 nm. The FT-IR technique confirms a metal-ligand interaction of Ag⁺ ions at a peak around 518 cm^-1. The structure and detailed morphology of AgNPs were confirmed using SEM and TEM techniques. Additionally, AgNPs exhibited substantial antibacterial activity against E. coli and S. aureus using the agar well diffusion method; the zone of inhibition was observed at 50, 100, and 150 μg/mL, respectively. The antioxidative property of AgNPs were tested using the DPPH radical scavenging assay at concentrations ranging from 100 to 500 μg/mL. The study underscores that the comprehensive characterization techniques that provide the synthesis of AgNPs from Calotropis gigantea leaf extract and their potential antibacterial and antioxidant properties pave the way for further development in the field.