Synergistic bactericidal activity of Ag-TiO 2 nanoparticles in both light and dark conditions Article uri icon


  • High-throughput screening was employed to evaluate bactericidal activities of hybrid Ag-TiO 2 nanoparticles comprising variations in TiO 2 crystalline phase, Ag content, and synthesis method. Hybrid Ag-TiO 2 nanoparticles were prepared by either wet-impregnation or UV photo deposition onto both Degussa P25 and DuPont R902 TiO 2 nanoparticles. The presence of Ag was confirmed by ICP, TEM, and XRD analysis. The size of Ag nanoparticles formed on anatase/rutile P25 TiO 2 nanoparticles was smaller than those formed on pure rutile R902. When activated by UV light, all hybrid Ag-TiO 2 nanoparticles exhibited stronger bactericidal activity than UV alone, Ag/UV, or UV/TiO 2. For experiments conducted in the dark, bactericidal activity of Ag-TiO 2nanoparticles was greater than either bare TiO 2 (inert) or pure Ag nanoparticles, suggesting that the hybrid materials produced a synergistic antibacterial effect unrelated to photoactivity. Moreover, less Ag %2b dissolved from Ag-TiO 2 nanoparticles than from Ag nanoparticles, indicating the antibacterial activities of Ag-TiO 2 was not only caused by releasing of toxic metal ions. It is clear that nanotechnology can produce more effective bactericides; however, the challenge remains to identify practical ways to take advantage of these exciting new material properties. © 2011 American Chemical Society.

publication date

  • 2011-01-01