Biogenic synthesis of selenium nanoparticles using garlic peel extract: a sustainable approach to enhanced antibacterial activity

Abstract Garlic peel (GP), an abundant agro-waste, remains largely unexplored as a biogenic source for selenium nanoparticle (SeNP) synthesis. This study investigates the antioxidant, anti-inflammatory, and antibacterial properties of GP-SeNPs and GP-extract. GP-SeNPs synthesized via reduction of sodium selenite using GP-extract were confirmed to be crystalline by X-ray diffraction, showing a characteristic absorption peak at 264 nm. Fourier transform infrared spectroscopy verified phytoconstituents responsible for nanoparticle synthesis, interaction, and stabilization. Scanning and transmission electron microscopy revealed predominantly spherical nanoparticles with an average diameter of 14.66 nm. Gas chromatography–mass spectrometry profiling identified multiple bioactive compounds, with palmitic and oleic acids as dominant constituents. GP-SeNPs exhibited markedly higher antioxidant and anti-inflammatory activities than GP-extract alone. Antibacterial assays demonstrated that GP-SeNPs exerted significantly stronger inhibitory effects than GP-extract against multidrug-resistant Staphylococcus aureus and Acinetobacter baumannii . This was evidenced by larger zones of inhibition, effective suppression of bacterial growth, and disruption of bacterial membranes, which caused leakage of proteins and DNA. Molecular docking showed strong binding affinities of palmitic and oleic acids toward bacterial DNA gyrase and topoisomerase IV, enhanced through nanoparticle conjugation. Overall, our findings demonstrate that GP-SeNPs are sustainable, agro-waste-derived bioactive nanomaterials with pronounced antibacterial activity, supported by measurable antioxidant and anti-inflammatory properties.