ABSTRACT
Zinc oxide (ZnO) nanoparticles were synthesized by a microwave method and were tailored using an energy electron irradiation method at 6.5 MeV. ZnO nanoparticles with a size of 40 nm were exposed to different fluences of 6.5 MeV electrons over the range from 5 × 1014 to 3.5 × 1015 electron/cm2. These electron-irradiated ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The XRD results showed that the ZnO nanoparticles retained the hexagonal phase with a wurtzite structure. However, the particle size decreased continuously from 40 to 15 nm with increasing electron fluence. The TEM results also supported for the reduction of the ZnO nanoparticles by 6.5 MeV electron irradiation. The antimicrobial activities of the as-synthesized and electron-irradiated ZnO nanoparticles on the fungus Candida albicans were studied. In this case, the electron-irradiated ZnO nanoparticles showed higher antimicrobial activity compared to that of the as-synthesized ZnO nanoparticles. The mechanism of killing biological cells was, however, the same for the as-synthesized and electron-irradiated nanoparticles.