title: Visible-light-induced bactericidal activity of a nitrogen-doped titanium photocatalyst against human pathogens.
abstract: 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.
authors.affiliation: Department of Materials Science and Engineering, National Dong-Hwa University, Hualien, Taiwan.
authors.forename: Ming-Show
authors.initials: MS
authors.lastname: Wong
authors.forename: Wen-Chen
authors.initials: WC
authors.lastname: Chu
authors.forename: Der-Shan
authors.initials: DS
authors.lastname: Sun
authors.forename: Hsuan-Shun
authors.initials: HS
authors.lastname: Huang
authors.forename: Jiann-Hwa
authors.initials: JH
authors.lastname: Chen
authors.forename: Pei-Jane
authors.initials: PJ
authors.lastname: Tsai
authors.forename: Nien-Tsung
authors.initials: NT
authors.lastname: Lin
authors.forename: Mei-Shiuan
authors.initials: MS
authors.lastname: Yu
authors.forename: Shang-Feng
authors.initials: SF
authors.lastname: Hsu
authors.forename: Shih-Lien
authors.initials: SL
authors.lastname: Wang
authors.forename: Hsin-Hou
authors.initials: HH
authors.lastname: Chang
mesh_terms: 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
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants; C009495:titanium dioxide; D014025:Titanium; D009584:Nitrogen