Photocatalytic and antibacterial activities of AgNPs from Mesua Ferrea seed

Abstract

The silver nanoparticles have been successfully prepared with Mesua ferrea seed extract by biological method. Characterizations have been made by XRD, FTIR, UV–Vis-NIR, FESEM with EDAX, DLS and HRTEM. Crystal structure and dislocation density were characterized by X-ray diffractometer and reveal that synthesized AgNPs were FCC structure and the size of AgNPs were 15 nm. Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Transmission Electron Microscope (HRTEM) characterizations were used to determine the morphology and size of the Ag nanoparticles in the range of 18–30 nm. The functional groups of AgNPs were identifying by FT-IR analysis. The UV–Vis-NIR spectral analysis is used to study optical behaviors like absorption and transmission properties of the AgNPs and optical bandgap of 2.7 eV. The dynamic light scattering (DLS) results confirm a good stabilization of the Ag nanoparticles. The photocatalytic activity of nanoparticles prepared via the biological method exhibited a higher photocatalytic activity compared to powders obtained by the hydrothermal method. The photocatalytic studies were evaluated for AgNPs by the degradation of Congo red under sunlight irradiation. The synthesized silver nanoparticles were tested against gram + Ve (Staphylococcus aureus and Bacillus subtilis) and gram − Ve (Salmonella typhi) bacteria for different concentrations like (10, 20, 30, and 40 μg/mL) and the results were discussed. The antimicrobial activity of AgNPs displayed a better zone of inhibition against selected human pathogens. The present study also investigated the toxicity effect of biogenic AgNPs against human lung adenocarcinoma cancer cells and normal human epithelial cells in vitro, and the inhibitory concentrations were found to be 30 and 40 μg/mL, respectively. We are anticipated a medicinal plant for the biological synthesis of AgNPs with the effective biomedical applications.