Evaluation and comparison of some green methods for synthesis of silver nanoparticles

Nowadays, there is an increasing need to develop high-yield, low cost, nontoxic, and eco-friendly procedures for synthesis of metallic nanoparticles. Therefore, the green synthesis methods become customary for synthesis of nanoparticles. Among metallic nanoparticles, nanosilver has developed because of its therapeutic properties. So in this paper, polysaccharide, tollens and biological green methods were investigated. In polysaccharide and tollens methods, starch and β-D glucose were used as a satabilizer and reducer respectively. In biological method biomass and cell filtrate of the Fusarium oxysporum fungus were used for the synthesis of nanoparticles. SEM images and UV-visible absorbtion spectra of these procedures showed that the polysaccharide method produced smaller silver nanoparticles wih high productivity. The changes of NADH-dependant nitrate reductase enzyme activity was evaluated in growh duration by colorometric Harely method due to importance of this enzyme in extracellular synthesis of silver nanoparticles. Results showed that the changes of dry cell mass impact on the enzyme activity.