Novel green synthesis of silver nanoparticles using Dillenia retusa with catalytic reduction and cytotoxicity analysis
摘要
This study reports for the first time the green synthesis of silver nanoparticles (AgNPs) using water extracts from parts of Dillenia retusa- leaf, fruit peel, flower, bark, stem and seed, a medicinal plant native to Sri Lanka, and evaluates their multifunctional potential through catalytic, and cytotoxic analysis. AgNP formation was confirmed by a characteristic colour change and a surface plasmon resonance peak between 400 and 480 nm. The scanning electron microscopy revealed predominantly spherical nanoparticles with sizes in the range of 60–70 nm, while particle size analysis indicated a relatively narrow size distribution with a mean diameter of approximately 65 nm and a low polydispersity index (PDI ≈ 0.289). Zeta potential measurements (≈–26 mV) suggested moderate colloidal stability. Catalytic studies demonstrated that flower_AgNPs possessed the most efficient reduction activity (k = 0.5464 min− 1) toward para-nitrophenol, a persistent nitroaromatic pollutant widely used as a model contaminant in wastewater remediation. Cytotoxicity screening showed no toxicity in Artemia salina, while Danio rerio embryos displayed clear dose-dependent effects, emphasizing both environmental compatibility at low concentrations and the importance of toxicity evaluation for biological use. Overall, D. retusa–mediated AgNPs demonstrate strong catalytic capacity and acceptable biological safety for therapeutic relevance, positioning them as promising multifunctional nanomaterials for wastewater remediation and exploratory biomedical research.