GREEN SYNTHESIS AND ANTIBACTERIAL EVALUATION OF SILVER NANOPARTICLES USING NEEM (AZADIRACHTA INDICA) LEAF EXTRACT

Abstract

The synthesis of silver nanoparticles (AgNPs) using traditional physical and chemical methods often involves toxic reagents, high energy consumption, and poor biocompatibility, making them unsuitable for many biomedical applications. Moreover, existing green synthesis approaches frequently lack control over nanoparticle size, shape, and stability, limiting their reproducibility and scalability. To address these limitations, this study employed a green synthesis route using Azadirachta indica (Neem) leaf extract as a natural reducing and stabilizing agent. Silver nitrate (AgNO₃) solutions of varying concentrations (1 mM, 5 mM, and 10 mM) were reacted with the Neem extract under ambient conditions. UV–Visible spectroscopy confirmed the formation of AgNPs with a characteristic surface plasmon resonance peak at 402 nm. Scanning Electron Microscopy (SEM) showed that the 5 mM AgNO₃ concentration produced the most desirable morphology, uniformly spherical nanoparticles with an average size of 98 nm. Energy Dispersive X-ray (EDX) analysis further confirmed the presence of pure elemental silver with no silver compounds. Moreover, antibacterial testing, conducted against Total Coliform bacteria and Propionibacterium acnes, revealed that the synthesized AgNPs, particularly in powder form, effectively inhibited bacterial growth over extended incubation periods. In conclusion, this study demonstrates that Neem-mediated synthesis is a viable, sustainable, and efficient approach for producing biologically active silver nanoparticles.