Synthesis, Characterization and Antibacterial Activity of ZnO Nanoparticles of Different Morphology

Abstract

Nanometric zinc oxide was prepared by sol-gel method using two different capping agents e.g., ethylene diamine (EDA) and citric acid (CAM) in different solvents. Nanorods of ZnO was prepared by sol-gel method using zinc nitrate hexahydrate (1M). The as-synthesized samples were characterized using XRD, FESEM-EDAX, TG/DTA techniques. FESEM micrographs suggest that the formation of nanorods of ZnO takes place for EDA and CAM in MeOH after calcination at 150 °C and 170 °C, respectively for 12h. The antibacterial activity tests (also known as plus-minus tests) were done by allowing bacteria to grow normally in laboratory conditions, and also by subjecting to ZnO nanoparticles in the powder form. On comparison of the above two Petri plates, the presence of a zone of inhibition indicates the antibacterial nature, which would have not existed if the bacteria did not experience any adverse effects by the presence of the ZnO nanorods. In the present study, the activity tested against Escherichia coli ATCC 25922 (gram-negative) Micrococcus leuteus and Bacillus subtilis (gram-positive) the results suggest the selective activity of the nanoparticles against these species.