Abstract
This study describes the synthesis, characterization and biocidal potential of copper oxide micro-spheres composed of thin sheets (CuOMSs-Ths). Microscopic observations of synthesized CuOMSs-Ths revealed the clusters of thin sheets arranged in small flower like micro-spheres. Diameter of each micro-sphere was determined in the range of 2-3 mu m, whereas the size of each sheet was similar to 80 nm. These micro-flowers like nanostructures were synthesized using copper nitrate hexahydrate and sodium hydroxide via solution process. The CuOMSs-Ths exhibited a broad-spectrum anti-bacterial activity involving significant growth inhibition of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Micrococcus luteus. The IC50 values of these engineered NPs against E. coli, P. aeruginosa, S. aureus and M. luteus were determined to be 195, 200, 131 and 184 mu g/ml respectively. Also, the respiration of Gram+ve organisms (M. luteus and S. aureus) was inhibited significantly (p value <0.005) at relatively lower concentrations of 12.5 and 50 mu g/ml, respectively, as compared to the Gram ye bacteria (E. coli and P. aeruginosa), where the growth inhibition occurred at a much greater concentration of 100 mu g/ml. The results explicitly demonstrated anti-microbial activity of CuOMSs-Ths with a higher level of toxicity against the Gram+ve vis-a-vis Gram ye bacteria. (C) 2013 Elsevier B.V. All rights reserved.