Abstract

• The development of eco-friendly process for the synthesis of nanoparticle is one of the main steps in the area of nanotechnology research. In this study, the synthesis of silver nanoparticles was conducted from silver nitrate (AgNO3) by using chitosan solution as reducing agent. Silver nanoparticles (Ag nanoparticles) were prepared by adding different volumes of silver nanoparticles (1mL,2mL,3mL,4mL) of 0.01M AgNO3 solution to various concentrations of chitosan solution (1% and 0.5% w/v). To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. The existence of nanoparticles in colloidal solution was confirmed by Tyndall effect. The synthesized silver nanoparticles were characterized by UVvisible spectroscopy, FT IR, SEM, XRD, EDXRF and determined their antimicrobial activities. The maximum absorption of prepared silver nanoparticles using chitosan solution as reducing agent were observed at the wavelengths of near 390 nm indicating the presence of Ag nanoparticles in colloidal solution. According to antimicrobial activity tests, Ag nanoparticles prepared using 1% (w/v) chitosan solution as reducing agent were found to be more active than 0.5%(w/v) chitosan solution. Among them, the Ag-nanoparticle prepared from 4mLof 0.01 M AgNO3 in 1% w/v of chitosan solution exhibit the highest activity on P.aeruginosa. From the SEM micrograph of this sample, the prepared Ag nanoparticles had spherical shape of various size. XRD analysis of Ag nanoparticles showed the amorphous form. The functional groups of Ag nanoparticles in this sample was identified by FT IR analysis which indicates the presence of Ag-O stretching and deformation. The relative abundance of silver in the prepared sample was investigated by EDXRF.