Synthesis, physical properties and antibacterial activity of metal oxides nanostructures

Metal oxides (MOs) nanostructures represent a new class of materials which have been explored for the health related applications. Highly ionic MOs nanostrucrures are important for their unique physicochemical properties as well as antibacterial activity. In this work, MOs nanostructures (ZnO, CuO, SnO2 and CeO2) have been synthesized by chemical co-precipitation technique and characterized by XRD, SEM, EDS, FTIR and UV-visible spectroscopy analysis. XRD results reveal the single-phase formation of all metal oxides. Spherical nanoparticles are observed in case of ZnO, SnO2 and CeO2 samples, while hierarchal nanostructures are observed in case of CuO sample. Antibacterial activity of four different MOs nanostructures against E. coli bacterium has been assessed by agar disc method. The antibacterial activity results have shown that the ZnO nanostructures exhibit maximum sensitivity (10 mm ZOI) towards E. coli bacterium. The order of antibacterial activity for different MOs nanostructures is found to be the following: ZnO > SnO2 > CeO2 > CuO. Our findings suggest that the particle size, morphology and type of MOs nanostructures play vital role in their antibacterial activity. It is concluded from the present findings that ZnO nanostructures can be used as an efficient antibacterial agent. (C) 2014 Elsevier Ltd. All rights reserved.