Controllable preparation and sterilization activity of zinc aluminium oxide nanoparticles

The zinc aluminium oxide (ZAO) NPs with homogeneous dispersion and crystal stability were prepared through synergistic reaction with ultrasonic-microwave and different dispersants. The products were characterized by X-ray diffraction analysis, transmission electron microscopy and UV–vis absorption spectra. The ZAO NPs of 45, 30, 25 and 20 nm in diameter could be controllably obtained under the same reaction conditions. These ZAO NPs were high crystalline and with wurtzite crystal structure. Specially, the sterilization activity of ZAO NPs was investigated firstly. Our bacteriological study showed the enhanced sterilization activity of ZAO NPs compared with ZnO NPs. This demonstrated that the bactericidal efficacy of ZAO NPs increases with decreasing particle size.