Visible-light-induced bactericidal activity of a nitrogen-doped titanium photocatalyst against human pathogens.
The antibacterial activity of photocatalytic titanium dioxide (TiO(2)) substrates is induced primarily by UV light irradiation. Recently, nitrogen- and carbon-doped TiO(2) substrates were shown to exhibit photocatalytic activities under visible-light illumination. Their antibacterial activity, however, remains to be quantified. In this study, we demonstrated that nitrogen-doped TiO(2) substrates have superior visible-light-induced bactericidal activity against Escherichia coli compared to pure TiO(2) and carbon-doped TiO(2) substrates. We also found that protein- and light-absorbing contaminants partially reduce the bactericidal activity of nitrogen-doped TiO(2) substrates due to their light-shielding effects. In the pathogen-killing experiment, a significantly higher proportion of all tested pathogens, including Shigella flexneri, Listeria monocytogenes, Vibrio parahaemolyticus, Staphylococcus aureus, Streptococcus pyogenes, and Acinetobacter baumannii, were killed by visible-light-illuminated nitrogen-doped TiO(2) substrates than by pure TiO(2) substrates. These findings suggest that nitrogen-doped TiO(2) has potential application in the development of alternative disinfectants for environmental and medical usages.
Wong
Ming-Show
MS
Department of Materials Science and Engineering, National Dong-Hwa University, Hualien, Taiwan.
Chu
Wen-Chen
WC
Sun
Der-Shan
DS
Huang
Hsuan-Shun
HS
Chen
Jiann-Hwa
JH
Tsai
Pei-Jane
PJ
Lin
Nien-Tsung
NT
Yu
Mei-Shiuan
MS
Hsu
Shang-Feng
SF
Wang
Shih-Lien
SL
Chang
Hsin-Hou
HH
D040981:Acinetobacter baumannii / Q000187:drug effects / Q000528:radiation effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000472:pathogenicity / Q000528:radiation effects*; D004202:Disinfectants / Q000494:pharmacology*; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D066298:In Vitro Techniques; D008027:Light; D008089:Listeria monocytogenes / Q000187:drug effects / Q000528:radiation effects; D009584:Nitrogen; D010777:Photochemistry; D012763:Shigella flexneri / Q000187:drug effects / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000187:drug effects / Q000528:radiation effects; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000528:radiation effects; D014025:Titanium / Q000494:pharmacology*; D014736:Vibrio parahaemolyticus / Q000187:drug effects / Q000528:radiation effects
D000900:Anti-Bacterial Agents; D004202:Disinfectants; C009495:titanium dioxide; D014025:Titanium; D009584:Nitrogen