Optimization, characterization and anti microbial activity of gold nano particles biosynthesized using aqueous extract of Sambucus ebulus L

Plants as stable and available sources to preparation of the biocompatible nano particles that have received much attention in recent years. The aim of this study were optimization and characterization of biosynthesis of gold nano particles (Au NPs) using leaf aqueous extract of Sambucus ebulus L. After preparing the extract, 2 ml of it, was added to 4 ml of HAuCl4.3H2O with concentration 1 mM, which reduced Au (III) ions to Au NPs, and quickly the color of solution changed to violet. In order to achieve Au NPs with a uniform shape and size, parameters affecting on synthesis such as: pH of the reaction, volume of plant extract, concentration of HAuCl4.3H2O solution, temperature and time of reaction were studied and optimized. All parameters were optimized using UV-Vis spectrophotometry. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were also employed to find characterization of the nanoparticles. Finally, the antibacterial properties of nanoparticles on 4 species of pathogenic bacteria such as: Staphylococcus aureus, Bacillus subtilis, E. coli and Salmonella enteritidis was evaluated by disc diffusion method and was reported as the diameter of inhibition zone. The results showed that the Au NPs showed a maximum absorbance at 534 nm. It was found that biosynthesized of Au NPs have spherical shape with a size between 11-17 nm and the gold nanoparticles have relatively good antibacterial activity against some bacteria.