Visible light inactivation of bacteria and fungi by modified titanium dioxide

Photochem Photobiol Sci. 2007 Jun;6(6):642-8. doi: 10.1039/b617043a. Epub 2007 Apr 2.


Visible light induced photocatalytic inactivation of bacteria (Escherichia coli, Staphylococcus aureus, Enterococcus faecalis) and fungi (Candida albicans, Aspergillus niger) was tested. Carbon-doped titanium dioxide and TiO2 modified with platinum(IV) chloride complexes were used as suspension or immobilised at the surface of plastic plates. A biocidal effect was observed under visible light irradiation in the case of E. coli in the presence of both photocatalysts. The platinum(IV) modified titania exhibited a higher inactivation effect, also in the absence of light. The mechanism of visible light induced photoinactivation is briefly discussed. The observed detrimental effect of photocatalysts on various microorganism groups decreases in the order: E. coli > S. aureus approximately E. faecalis>>C. albicans approximately A. niger. This sequence results most probably from differences in cell wall or cell membrane structures in these microorganisms and is not related to the ability of catalase production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / drug effects
  • Bacteria / radiation effects*
  • Fungi / drug effects
  • Fungi / radiation effects*
  • Light*
  • Photochemistry
  • Photosensitizing Agents / chemistry
  • Photosensitizing Agents / pharmacology*
  • Platinum Compounds / chemistry
  • Titanium / chemistry
  • Titanium / pharmacology*


  • Photosensitizing Agents
  • Platinum Compounds
  • platinum chloride
  • titanium dioxide
  • Titanium