Photocatalytic disinfection using titanium dioxide : spectrum and mechanism of antimicrobial activity

Foster, HA; Ditta, IB; Varghese, S; Steele, A

Abstract

The photocatalytic properties of titanium dioxide
are well known and have many applications
including the removal of organic contaminants and
production of self-cleaning glass. There is an increasing
interest in the application of the photocatalytic properties
of TiO2 for disinfection of surfaces, air and water.
Reviews of the applications of photocatalysis in disinfection
(Gamage and Zhang 2010; Chong et al., Wat Res 44
(10):2997–3027, 2010) and of modelling of TiO2 action
have recently been published (Dalrymple et al. , Appl
Catal B 98(1–2):27–38, 2010). In this review, we give an
overview of the effects of photoactivated TiO2 on microorganisms.
The activity has been shown to be capable of
killing a wide range of Gram-negative and Gram-positive
bacteria, filamentous and unicellular fungi, algae, protozoa,
mammalian viruses and bacteriophage. Resting
stages, particularly bacterial endospores, fungal spores
and protozoan cysts, are generally more resistant than the
vegetative forms, possibly due to the increased cell wall
thickness. The killing mechanism involves degradation of
the cell wall and cytoplasmic membrane due to the
production of reactive oxygen species such as hydroxyl
radicals and hydrogen peroxide. This initially leads to
leakage of cellular contents then cell lysis and may be
followed by complete mineralisation of the organism.
Killing is most efficient when there is close contact
between the organisms and the TiO2 catalyst. The killing
activity is enhanced by the presence of other antimicrobial
agents such as Cu and Ag.

Citation

Foster, H., Ditta, I., Varghese, S., & Steele, A. (2011). Photocatalytic disinfection using titanium dioxide : spectrum and mechanism of antimicrobial activity. Applied Microbiology and Biotechnology, 90(6), 1847-1868. https://doi.org/10.1007/s00253-011-3213-7

• Journal Article Type: Article
• Publication Date: Jan 1, 2011
• Deposit Date: Oct 18, 2011
• Journal: Applied Microbiology and Biotechnology
• Print ISSN: 0175-7598
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 90
• Issue: 6
• Pages: 1847-1868
• DOI: https://doi.org/10.1007/s00253-011-3213-7
• Publisher URL: http://dx.doi.org/10.1007/s00253-011-3213-7