Insightful Characterization of Biosynthesized Ag‐NPs Using <i>Daphniphyllum neilgherrense</i> Leaf Extract and Exploring Novel Avenues in Biomedical and Environmental Fields

Abstract For the first time, the biosynthesis of Ag‐NPs with the Daphniphyllum neilgherrense leaf extract was done in this work. Spectroscopic and microscopic instrumentations were used to investigate the physico‐chemical properties of the synthesized Ag‐NPs to confirm their formation, size, morphology, and surface functionalization. The study examined the antimicrobial, antioxidant and cytotoxic properties of D. neilgherrense synthesized Ag‐NPs. The biocatalytic activity of Ag‐NPs was evaluated using methylene blue, an organic dye pollutant. The synthesized Ag‐NPs demonstrated significant inhibitory effects against bacterial and fungal pathogens. The antioxidant potential of Ag‐NPs was evaluated using the DPPH, reducing power and ABTS assays which demonstrated significant free radical scavenging activity. Compared with the standard drug rutin, at 100 µg/mL concentration, the Ag‐NPs showed better inhibition percentage: DPPH radical scavenging activity (IC 50 = 88.70%), OD value of reducing power assay (2.4763), and ABTS radical scavenging activity (IC 50 = 87.08%). The anticancer activity of the Ag‐NPs assessed against human breast cancer cell line MDA MB‐231 revealed more cytotoxic impact and its IC 50 was 42.28 µg/mL. The photocatalytic activity of the Ag‐NPs was evaluated under UV irradiation, demonstrating significant degradation of methylene blue. The findings also showed 91.3% methylene blue dye catalysis at 150 min by the green synthesized Ag‐NPs.