Study On The Synthesis Of Colloidal Silver Nanoparticles By Γ-Irradiation Using Chitosan Stabilizer

Radiation-induced synthesis of colloidal silver nanoparticles using chitosan as a stabilizer and free radical scavenger is feasible and according to green method. The saturated conversion dose (Ag+ to Ag0) was determined by Uv-vis spectroscopy and silver nanoparticles size was characterized by transmission electron microscopy (TEM). The average diameter of silver nanoparticles is smaller than 10 nm with narrow size distribution and the colloidal silver nanoparticles has good stability for a long time of storage. The effect of Ag+ and chitosan concentration and molecular weight of chitosan on diameter and size distribution of silver nanoparticles was investigated. Silver nanoparticles of about 7 nm stabilized by chitosan showed high antimicrobial effect. The inhibition of Staphylococcus aureus is more than 99.9% (from 107 CFU/ml to 103 CFU/ml at 5 ppm). The antifungal effect particularly on Corticium salmonicolor attains to medium level (ED50 = 27.16 ppm) and the inhibition percent is of 70-80% for silver nanoparticles concentration from 40 to 100 ppm. (author)