LAUSR

Abstract In recent years, the application of bioengineering methods has attracted special focus because of simplicity, low cost, high efficiency, non-toxicity, and environmental compatibility. The present study is the first report of biosynthesis of silver nanoparticles (SNPs) using Boerhavia elegans (choisy). 2 mL of extract was added to 4 mL of AgNO 3 with concentration of 1 mM. In order to obtain nanoparticles (NPs) with uniform shape and size, factors affecting the synthesis of NPs, such as: pH of reaction, volume of extract, concentration of silver (I), temperature and time of reaction were evaluated and optimized using UV–Vis spectrophotometry. To characterize the NPs, Transmission Electron Microscopy (TEM) and Power X-ray Diffraction (PXRD) and Fourier-Transformed Infrared Spectroscopy techniques were used. Finally, the antimicrobial activities of SNPs were investigated on four and two pathogenic bacteria and fungi using disc diffusion method. The SNPs showed Surface Plasmon Resonance centered at 405 nm. The PXRD pattern and TEM analysis revealed spherical, stable, and uniform SNPs with the average particle size of 15 nm. The antimicrobial activity of the synthesized SNPs showed a significant microbial effect on all clinical isolates especially, bacteria and fungi. These results suggest that such stable and uniform SNPs can be synthesized rapidly and simply for clinical as well as pharmaceutical applications. Graphic Abstract