Catalytic sterilization of Escherichia coli K 12 on Ag/Al2O3 surface.
Bactericidal action of Al(2)O(3), Ag/Al(2)O(3) and AgCl/Al(2)O(3) on pure culture of Escherichia coli K 12 was studied. Ag/Al(2)O(3) and AgCl/Al(2)O(3) demonstrated a stronger bactericidal activity than Al(2)O(3). The colony-forming ability of E. coli was completely lost in 0.5 min on both of Ag/Al(2)O(3) and AgCl/Al(2)O(3) at room temperature in air. The configuration of the bacteria on the catalyst surface was observed using scanning electron microscopy (SEM). Reactive oxygen species (ROS) play an important role in the expression of the bactericidal activity on the surface of catalysts by assay with O(2)/N(2) bubbling and scavenger for ROS. Furthermore, the formation of CO(2) as an oxidation product could be detected by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and be deduced by total carbon analysis. These results strongly support that the bactericidal process on the surface of Ag/Al(2)O(3) and AgCl/Al(2)O(3) was caused by the catalytic oxidation.
Chen
Meixue
M
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Yan
Lizhu
L
He
Hong
H
Chang
Qingyun
Q
Yu
Yunbo
Y
Qu
Jiuhui
J
D000537:Aluminum Oxide; D002384:Catalysis; D015169:Colony Count, Microbial; D048168:Escherichia coli K12 / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D017382:Reactive Oxygen Species; D012834:Silver; D017550:Spectroscopy, Fourier Transform Infrared; D013242:Sterilization / Q000379:methods*; D013482:Superoxide Dismutase
D017382:Reactive Oxygen Species; D012834:Silver; D013482:Superoxide Dismutase; D000537:Aluminum Oxide