Green synthesis, characterization of silver nanoparticles using Rhynchosia capitata leaf extract and their biological activities

Green production of silver nanoparticles (AgNPs) using biological samples is the most cost-effective and environment friendly method. Plants and other biological resources might be exploited to create biologically active AgNPs. Rhynchosia capitata (an endangered species) leaf extract acted as reductant in fabrication of AgNPs in the current study; while, the fabricated particles have been characterized by UV-visible spectrophotometry, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). UV-visible spectroscopy was utilized to confirm the fabrication of the nanoparticles (NPs) via bioreduction. SEM revealed the formation of round and spherical AgNPs with sizes ranging from 2 to 60 nm. According to TGA, the synthesized R. capitata AgNPs were not much stable and high mass loss was observed at temperature from 40 to 80?. The antioxidant potential was higher as estimated through 2,2-diphenyl-1-picrylhydrazyl-hydrate assay with IC50 value of 60 mu g/mL rather than 2,2-azinobis-[3-ethylbenzthiazoline]-6-sulfonic acid assay (IC50 120 mu g/mL). The antibacterial potential against the selected bacterial strains for NPs was high as compared to aqueous extract, determined through agar well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration methods. These findings demonstrated that R. capitata-based NPs had greater antibacterial and antioxidant properties than plant extract and it should be potentially used as antibacterial and antioxidant agents.