Highly effective antibacterial properties of self-formed Ag nanoparticles/Zr-Ag granular films

[Display omitted] •A convenient method prepared Ag NPs/Zr-Ag films with high-effective antibacterial properties.•Synergistic effect of Ag NPs and Ag+ enhances the antibacterial properties of Zr-Ag films.•A great number of “clean” monodisperse Ag NPs are self-assembled on different substrates.•Zr addition promotes the self-assembly of Ag NPs on the film surface. Zr-Ag granular films are prepared by magnetron sputtering, on which monodisperse Ag nanoparticles are controllably fabricated through thermal annealing the thin films. The self-formation behaviors of Ag nanoparticles are temperature and Ag content dependent. At the annealing temperature of 360 ℃, the Zr-41.0 wt% Ag granular films have the highest number density of Ag nanoparticles. In vitro antibacterial experiments show that the Ag nanoparticles/Zr-Ag granular films exhibit an excellent antibacterial property, even more than 99.99% for both Escherichia coli and Staphylococcus aureus. The remarkable antibacterial activity can be ascribed to the release of Ag+ from Ag nanoparticles/Zr-Ag granular films and mechanical antibacterial effect of Ag nanoparticles. The results are helpful to the flexible fabrication and development of granular films with high antibacterial performances on different substrates.