Journal of Advances in Nanomaterials

7

Authors: Asmathunisha. N, Anburaj. R, Kathiresan. K

The present study investigated the biosynthesis of silver and gold nanoparticles by marine cyanobacteria derived from coastal mangrove sediment of southeast India. Marine cyanobacteria were able to produce both silver and gold nanoparticles, as confirmed by visual observation, UV-Vis spectroscopy. Appearance of brown colour is an indication of silver nanoparticles, while ruby colour indicates the synthesis of gold nanoparticles in the reaction mixture. Control without silver nitrate and tetra chloro auric acid did not exhibit any colour change. The nanoparticles synthesized were mostly cubical, ranging in size from 70 to 85 nm for both silver and gold nanoparticles as evident by scanning electron microscopy (SEM) and Atomic force microscopy (AFM). The X-ray diffraction pattern confirmed the presence of crystallized nature of nanoparticles. Zeta potential value (-49.10 mV) of the silver nanoparticles and (-64.32 mV) of the gold nanoparticles revealed good stability of the nanoparticles up to 2 months. This work highlighted the possibility of using mangrove derived cyanobacteria for synthesis of silver and gold nanoparticles.