Bactericidal mechanisms of Ag₂O/TNBs under both dark and light conditions.
Ag(2)O/TNBs were fabricated by depositing Ag(2)O nanoparticles on the surface of TiO(2) nanobelts (TNBs). The disinfection activities of Ag(2)O/TNBs on two representative bacterial types: Gram-negative Escherichia coli ATCC15597 and Gram-positive Bacillus subtilis, were examined under both dark and visible light conditions. Ag(2)O/TNBs exhibited stronger bactericidal activities than Ag(2)O nanoparticles and TNBs under both dark and light conditions. For both cell types, disinfection effects of Ag(2)O/TNBs were greater under light conditions relative to those under dark conditions. The bactericidal mechanisms of Ag(2)O/TNBs under both dark and light conditions were explored. Ag(+) ions released from Ag(2)O/TNBs did not contribute to the bactericidal activity of Ag(2)O/TNBs under dark conditions, whereas the released Ag(+) ions showed bactericidal activity under visible light irradiation conditions. Active species (H(2)O(2), O(2)(-)·, and e(-)) generated by Ag(2)O/TNBs played important roles in the disinfection processes under both dark and visible light irradiation conditions. Without the presence of active species, the direct contact of Ag(2)O/TNBs with bacterial cells had no bactericidal effect.
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
Yinjia
Y
Jin
Zhaoyi
Z
Dai
Fei
F
Liu
Hyunjung
H
Kim
Meiping
M
Tong
Yanglong
Y
Hou
D000693:Anaerobiosis / Q000187:drug effects / Q000528:radiation effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000528:radiation effects; D003624:Darkness; D004203:Disinfection; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008027:Light; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000494:pharmacology*; D018030:Silver Compounds / Q000494:pharmacology*; D014025:Titanium / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010087:Oxides; D018030:Silver Compounds; C009495:titanium dioxide; C040225:disilver oxide; D006861:Hydrogen Peroxide; D014025:Titanium