Bactericidal effect of Al2O3-supported Ag catalyst

The bactericidal effect of the Al2O3-supported Ag catalyst (Ag/Al2O3 and AgCl/Al2O3) against E. coli in air was investigated. The results indicated that the colony-forming ability of E. coli was completely lost on the catalyst. The toxicity of Ag+ eluted from the catalyst could be ignored under the experimental conditions. The results with and without the presence of oxygen showed that Ag promoted the transformation of oxygen molecules to reactive oxygen species (ROS), and ROS destroyed the cell membrane of E. coli through oxidation. Thus the existence of oxygen was a fatal factor to the bactericidal effect of Ag/Al2O3 and AgCl/Al2O3 Scanning electron microscopy confirmed that the primary breakage of cells was on the membrane.