Biosynthesis and characterization of Gynocardia odorata R. Br. mediated silver nanoparticles and evaluation of its antimicrobial activity

The present study was designed to synthesize Silver Nanoparticles (Ag-NPs) in aqueous medium using leaf extract of Gynocardia odorata R. Br. (Achariaceae). The synthesized Ag-NPs were characterized using different technique such as UV-Visible Spectroscopy, X-Ray Diffraction (XRD) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM). The reduction of Ag ions to initiate nucleation and subsequent Ostwald Ripening to form nanoparticles was made possible by the presence of various antioxidants in the leaves of Gynocardia odorata. These antioxidants served both as reducing and capping agents. The synthesized Ag-NPs were found to be polydispersed in nature and spherical in shape. With the Surface Plasmon Resonance (SPR) optical absorption band peak at ~440 nm was observed using UV-Vis spectrophotometer. FTIR confirmed the presence of methoxy and allyl groups in the synthesized Ag-NPs and nearly 15-45 nm diameter spherical shaped NPs was validated using TEM. The synthesized Ag-NPs were stable for a long period (more than six months) and showed good antibacterial activity against both gram positive and gram negative bacterial strains and the effect was higher as compared to the normal aqueous extract