M. Vanaja, S. Rajeshkumar, K. Paulkumar, G. Gnanajobitha, C. Malarkodi and G. Annadurai
Green synthesis method of nanoparticles is evolution from the nanobiotechnology. It is a low cost, environment benign, non toxic and large scale up process. In this study, Coleus aromaticus leaf extract was used to the bioreduction of silver ions to nanoparticles. Bioreduction process was carried out to study about the factors affecting the nanoparticles synthesis by changing the silver ion concentration, pH and temperature. 1 mM silver ion concentration, pH 8.2 and temperature 70 ºC is more favorable for maximum production of silver nanoparticles. UV-vis spectrum was used to characterize these synthesized silver nanoparticles and the SPR band was observed at 460 nm indicates particles are poly dispersed. Size and shape of nanoparticles was analyzed by Scanning electron microscope (SEM) shows polydispersed and mostly spherical shape of nanoparticles with aggregation. This green synthesis method has many advantages over the chemical method because it reduces the use of toxic metals in the synthesis process and it is a single step eco-friendly method
