Visible-light-induced bactericidal activity of a nitrogen-doped titanium photocatalyst against human pathogens

Appl Environ Microbiol. 2006 Sep;72(9):6111-6. doi: 10.1128/AEM.02580-05.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / radiation effects
  • Anti-Bacterial Agents / pharmacology*
  • Bacteria / drug effects*
  • Bacteria / pathogenicity
  • Bacteria / radiation effects*
  • Disinfectants / pharmacology*
  • Environmental Microbiology
  • Escherichia coli / drug effects
  • Escherichia coli / radiation effects
  • Humans
  • In Vitro Techniques
  • Light
  • Listeria monocytogenes / drug effects
  • Listeria monocytogenes / radiation effects
  • Nitrogen
  • Photochemistry
  • Shigella flexneri / drug effects
  • Shigella flexneri / radiation effects
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / radiation effects
  • Streptococcus pyogenes / drug effects
  • Streptococcus pyogenes / radiation effects
  • Titanium / pharmacology*
  • Vibrio parahaemolyticus / drug effects
  • Vibrio parahaemolyticus / radiation effects


  • Anti-Bacterial Agents
  • Disinfectants
  • titanium dioxide
  • Titanium
  • Nitrogen