Remarkable antibacterial properties of copper and its oxide thin films against E coli

The Cu and Cu ₂O thin films with particle sizes of about 20-50 nm were prepared on the quartz substrate, using DC sputtering technology with a copper target by adjusting oxygen and argon flow rate, and the interactions of Escherichia coli with the thin films were studied. The optical properties, crystal structure, morphology of the samples had been studied by UV-Vis spectrophotometer, grazing incidence small-angle X-ray diffraction (GIXRD) and SEM, respectively. The results exhibited that both Cu and Cu ₂O thin films had remarkable antibacterial properties against E coli. Besides metal ions antibacterial effect, Cu ₂O thin films also shows strongly photocatalytic inactivation effect under solar light irradiation. Because of solar light irradiation, metal Cu partially oxidized to Cu ₂O on the surface, which enhanced the antibacterial efficiency.