Silver nanoparticles, green synthesis: characterization, in vitro antioxidant and antimicrobial study

Abstract

The present study reports a rapid green synthesis of silver nanoparticles using Skimmia laureola stem bark aqueous extract as reducing and stabilizing agent. When bark extract was mixed with AgNO3 solution, the color of the solution was changed from light pale yellow to dark brown, a sign of formation of silver nanoparticles (AgNPs). UV-Visible spectra of AgNPs colloidal suspensions showed absorption peak from 422 to 461 nm that indicated the formation of AgNPs. The experimental results indicated that XRD pattern showed the crystalline nature and SEM images showed predominantly spherical shape of green synthesized AgNPs. FASS analysis showed rapid reduction of silver ions to AgNPs (almost 90% within 3 h) and FTIR analysis exhibited capping of AgNPs by bioactive compounds from S. laureola bark. Furthermore, AgNPs exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacteria. Significant antioxidant activity was also represented by AgNPs and stem bark aqueous extract.