Roussin's black salt decorated Cu-doped ZnO nanoparticles for bacterial inhibition

Antibacterial RBS@Cu:ZnO nanoparticles (NPs) were prepared by decorating Cu-doped ZnO NPs with Roussin's black salt (RBS), a nitric oxide (NO) precursor. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) tests indicated that the RBS@Cu:ZnO NPs were particulate matter with crystal morphology and nanoscaled sizes. X-ray diffraction (XRD) patterns revealed the wurtzite crystal structure of the NPs. Under irradiation of 543 nm laser, the RBS@Cu:ZnO NPs released NO in a controllable manner due to the decomposition of RBS. Cu-doped ZnO with a Cu/Zn molar ratio of 5% showed antibacterial activity in response to ultraviolet and visible light by photocatalysis. The doping of Cu enhanced the visible light absorption of ZnO by reducing its band gap. The RBS@Cu:ZnO NPs exhibited high antibacterial activity originating from the synergistic bacterial inhibitory effects of Cu-doped ZnO and released NO under visible laser irradiation. More importantly, the antibacterial activity could be controlled by adjusting the power output of laser irradiation. The RBS@Cu:ZnO NPs are promising antibacterial agents with potential applications in biomedicine and pharmaceutics.