Characterization and antibacterial activity of green synthesized silver nanoparticles from Cryptocarya wightiana Thw. leaves

Abstract

Green synthesis of nanoparticles using plant extracts offers a sustainable approach for producing bioactive nanomaterials. In this study, silver nanoparticles (AgNPs) were synthesized using the methanolic leaf extract of Cryptocarya wightiana, a plant rich in phenolics, flavonoids, alkaloids, and other bioactive compounds. GC-MS analysis revealed several major phytochemicals, including cis-9-hexadecenal, hexadecanal, and n-hexadecanoic acid, some of which are reported here for the first time. The synthesized AgNPs were characterized using UV-Visible spectroscopy, FTIR, SEM-EDX, XRD, DLS, and zeta potential analysis, confirming the formation of predominantly spherical, crystalline nanoparticles with an average size of ~6.2 nm. The AgNPs exhibited notable antibacterial activity against Staphylococcus aureus and Xanthomonas campestris, with higher efficacy against S. aureus. These findings highlight C. wightiana as a promising source for eco-friendly synthesis of bioactive nanoparticles with potential applications in antimicrobial therapy and nanobiotechnology.