title: Photocatalytic antimicrobial activity of thin surface films of TiO(2), CuO and TiO (2)/CuO dual layers on Escherichia coli and bacteriophage T4.
abstract: TiO(2)-coated surfaces are increasingly studied for their ability to inactivate microorganisms. The activity of glass coated with thin films of TiO(2), CuO and hybrid CuO/TiO(2) prepared by atmospheric Chemical Vapour Deposition (Ap-CVD) and TiO(2) prepared by a sol-gel process was investigated using the inactivation of bacteriophage T4 as a model for inactivation of viruses. The chemical oxidising activity was also determined by measuring stearic acid oxidation. The results showed that the rate of inactivation of bacteriophage T4 increased with increasing chemical oxidising activity with the maximum rate obtained on highly active sol-gel preparations. However, these were delicate and easily damaged unlike the Ap-CVD coatings. Inactivation rates were highest on CuO and CuO/TiO(2) which had the lowest chemical oxidising activities. The inactivation of T4 was higher than that of Escherichia coli on low activity surfaces. The combination of photocatalysis and toxicity of copper acted synergistically to inactivate bacteriophage T4 and retained some self-cleaning activity. The presence of phosphate ions slowed inactivation but NaCl had no effect. The results show that TiO(2)/CuO coated surfaces are highly antiviral and may have applications in the food and healthcare industries.
authors.affiliation: Biomedical Sciences Research Institute, University of Salford, Salford, UK.
authors.forename: Iram B
authors.initials: IB
authors.lastname: Ditta
authors.forename: Alex
authors.initials: A
authors.lastname: Steele
authors.forename: Christopher
authors.initials: C
authors.lastname: Liptrot
authors.forename: Julie
authors.initials: J
authors.lastname: Tobin
authors.forename: Helen
authors.initials: H
authors.lastname: Tyler
authors.forename: Heather M
authors.initials: HM
authors.lastname: Yates
authors.forename: David W
authors.initials: DW
authors.lastname: Sheel
authors.forename: Howard A
authors.initials: HA
authors.lastname: Foster
mesh_terms: D017122:Bacteriophage T4 / Q000187:drug effects*; D003300:Copper / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects*; D005898:Glass; D050296:Microbial Viability; D010084:Oxidation-Reduction; D010782:Photolysis; D013229:Stearic Acids / Q000378:metabolism; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays; D010948:Viral Plaque Assay; D038301:Virus Inactivation
chemical_list: D004202:Disinfectants; D013229:Stearic Acids; C009495:titanium dioxide; D003300:Copper; D014025:Titanium; C030973:cupric oxide