Construction of Ag-decorated ZnO with oxygen vacancies for enhanced antibacterial activity via increased H₂O₂...

Ag-decorated ZnO nanorods with different Ag contents were prepared by deposition-precipitation method, which demonstrated enhanced inhibition ability for the common pathogen, especially exhibited excellent antibacterial effects on clinical drug resistant bacteria. Moreover, Ag-decorated ZnO nanorods presented much lower cytotoxicity to HEK293 cell than that of silver nanoparticles (AgNPs). The electron spin resonance (ESR) spectra revealed that oxygen vacancies (V_O) were formed in ZnO after the decoration of AgNPs. To understand the improved antibacterial activity of Ag-decorated ZnO nanorods, reactive oxygen species (ROS) were determined. It was found that more H₂O₂ were generated over Ag-decorated ZnO compared to pure ZnO, which was closely related to the oxygen vacancy (V_O) concentration. The production of large amount of H₂O₂ resulted in more serious membrane leakage of cytosol and dehydrogenation inactivation of respiratory chain for bacterial, thus leading to the enhanced antibacterial activities of Ag-decorated ZnO nanorods.