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

Zr-Ag granular films are prepared by magnetron sputtering, on which monodisperse Ag nanoparticles are con-trollably 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 celcius, 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 perfor-mances on different substrates.