Robust and fluorescent silver nanoparticles using Artemisia annua: Biosynthesis, characterization and antibacterial activity

Metal nanoparticles have been studied extensively because of their unique physicochemical properties. Among the metal nanoparticles, silver nanoparticles have gained much interest over the last few years due to its good conductivity, chemical stability, catalytic and antimicrobial activity. In this study, fluorescent silver nanoparticles were synthesized using Artemisia annua leaf extract. After exposing the silver ions to the leaf extract, the rapid reduction of silver ions led to the formation of silver nanoparticles in solution. The synthesis was completed within 5 min. The synthesized fluorescent silver nanoparticles were characterized by UV-vis, fluorescence spectroscopy TEM, EDX, XRD, and FTIR. The antibacterial activity of the nanoparticles against gram negative and gram positive bacterial strains were studied. The antibacterial effect was studied by MIC and disk diffusion assay. The stability of fluorescent silver nanoparticles in biological media was demonstrated with the resistance to oxidation by the addition of H2O2. TEM analysis of fluorescent silver nanoparticles treated bacterial cells reveals that the silver nanoparticles exert antibacterial activity by disrupting the cell membrane structure and integrity. The biosynthesized silver nanoparticles were biocompatible which were confirmed by checking the cytotoxicity against human erythrocytes. The silver nanoparticles showed significant fluorescence and antibacterial activity, indicating that has the potential to be used in the development of value-added products in the biomedical and nanotechnology-based industries. (C) 2015 Elsevier B.V. All rights reserved.