Comparative study on silver nanoparticles properties produced by green methods

Abstract

In the present study, properties of silver nanoparticles (AgNPs) such as average size, size distribution and<br />morphology were investigated by Tollens, polysaccharide, modified polysaccharide and microbial methods.<br />The synthesized AgNPs were characterized by UV-visible spectroscopy, scanning electron microscopy<br />(SEM), transmission electron microscopy (TEM), dynamics light scattering (DLS) and energy dispersive<br />X-ray (EDX) analyses. Analysis of reaction mixtures confirmed that Tollens, polysaccharide and modified<br />polysaccharide methods generated smaller AgNPs with better size distribution as compared to that produced<br />in microbial method. The average size of produced AgNPs by Tollens, polysaccharide and modified<br />polysaccharide were 42, 30 and 20 nm respectively. Moreover, microbial method generated AgNPs with average size of 54 nm in the case of cell-free filtrate mediated synthesis and 84 nm in case of the supernatant mediated synthesis. Analysis of fungus-mediated synthesis of AgNPs showed that the size distribution of AgNPs produced by supernatant is narrower than that produced by filtrate. Also, cell-free filtrate<br />resulted in the formation of smaller AgNPs with average size of 59 nm compared to the supernatant. The<br />comparative analysis of produced AgNPs by the above mentioned methods confirmed that modified polysaccharide method led to the formation of AgNPs with smallest size and highest productivity.