Bactericidal properties of nanoscale zinc(II) and titanium (IV) oxides of different nature and their nanocomposites with polystyrene

Resumo

The samples with nano-titanium dioxide (X-ray amorphous, η-modification, Degussa P25 mixture of rutile and anatase, Hombifine N, and Hombikat UV100 with anatase) and hexagonal nano-ZnO both in pure form and as a part of polystyrene (PS) nanocomposites were studied for antibacterial activity in the dark against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Bacillus antracoides, and Candida albicans microorganisms by the Kirby-Bauer disk diffusion method. Among the starting samples, ZnO exhibits ABA against all bacterial cultures in use; the sample with the η-phase exhibits ABA against Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus antracoides; the X-ray amorphous TiO₂ exhibits ABA against Staphylococcus aureus and Candida albicans; and the remaining samples have no ABA. The diameters of the microbial growth retardation zone for the η-phase/PS, X-ray amorphous TiO₂/PS, and ZnO/PS nanocomposites were found to be less than those for the starting oxides; the range of microbes inhibited by ZnO/PS was smaller since it exhibited no ABA against Candida albicans, while such activity remained in the X-ray amorphous TiO₂/PS nanocomposite.