Antimicrobial power of Cu/Zn mixed oxide nanoparticles to Escherichia coli

Abstract The antimicrobial power of a Cu/Zn mixed oxide was probed by viability study against E. coli . A facile, environment friendly synthesis of CuO, ZnO and Cu 0.73 Zn 0.27 O nanoparticles was carried out via hydroxycarbonate precursors and the samples characterized by several techniques. The antimicrobial efficacy of the nanoparticles was, then, probed by two independent growth inhibition essays, the culture methods and the optical density after 4 h, 8 h and 24 h contact time and shows both a time and concentration dependency. Remarkably the Cu 0.73 Zn 0.27 O mixed oxide exhibits the highest antimicrobial activity, with 90% growth inhibition already after 8 h for a dose of 200 μg/mL whereas CuO reaches the same performance only after 24 h and ZnO has, comparatively, only a limited activity.