Green Synthesis of Silver Nanoparticles Using Plant Extracts: Characterization and Antimicrobial Potential

Abstract

The increasing demand for eco-friendly nanomaterial synthesis has driven the exploration of plant-mediated approaches, offering an alternative to conventional chemical and physical methods. This study investigates the green synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Azadirachta indica (neem) as both a reducing and stabilizing agent. The synthesis was conducted by mixing silver nitrate solution with the plant extract under ambient conditions, resulting in a visible color change from pale yellow to dark brown, indicative of nanoparticle formation. The synthesized AgNPs were characterized using UV–Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). UV–Vis spectra showed a characteristic surface plasmon resonance peak at 430 nm. FTIR analysis confirmed the presence of phytochemical functional groups responsible for reduction and stabilization. XRD patterns indicated crystalline nature, and TEM imaging revealed predominantly spherical nanoparticles with sizes ranging from 12 to 25 nm. The antimicrobial activity of the synthesized AgNPs was assessed against Escherichia coli and Staphylococcus aureus using the disc diffusion method. Significant zones of inhibition were observed, demonstrating potent antibacterial properties. The study highlights the potential of plant-based synthesis as a sustainable, cost-effective, and environmentally friendly approach for producing nanoparticles with biomedical applications. These findings pave the way for further research on optimizing synthesis parameters, scaling production, and exploring the use of other medicinal plants for nanomaterial fabrication.

Keywords: Green Synthesis, Silver Nanoparticles, Azadirachta indica, Antimicrobial Activity, Nanotechnology, Sustainable Chemistry

. https://doi.org/10.5281/zenodo.17119964