Bacterial Biofilm Characterization and Microscopic Evaluation of the Antibacterial Properties of a Photocatalytic Coating Protecting Building Material

Abstract

Abstract:Use of photocatalytic paint-like coatings may be a way to protect building materials from microbial colonization. Numerous studies have shown the antimicrobial efficiency of TiO 2 photocatalysis on various microorganisms. However, few have focused on easy-to-apply solutions and on photocatalysis under low irradiance. This paper focuses on (a) the antibacterial properties of a semi-transparent coating formulated using TiO 2 particles and (b) the microscopic investigations of bacterial biofilm development on TiO 2 -coated building materials under accelerated growth conditions. Results showed significant antibacterial activity after few hours of testing. The efficiency seemed limited by the confinement of the TiO 2 particles inside the coating binder. However, a pre-irradiation with UV light can improve efficiency. In addition, a significant effect against the formation of a bacterial biofilm was also observed. The epifluorescence approach, in which fluorescence is produced by reflect rather than transmitted light, could be applied in further studies of microbial growth on coatings and building materials.

The Response of Pseudomonas aeruginosa PAO1 to UV-activated Titanium Dioxide/Silica Nanotubes

“…The literature data indicate that such irradiation can induce a photocatalytic reaction in TiO 2 that was deposited in the mesopores of silica nanotubes. In that case, the irradiated nanomaterial releases radicals that can cause oxidative stress to the microorganisms by the generation of superoxide, hydroxyl, and singlet oxygen radicals [ 35 , 36 ]. This explains the reduced agglomeration in samples that were not irradiated and suggests that cells were agglomerating in response to oxidative stress.…”

“…This result is surprising in the light of data indicating the antibacterial activity of TiO 2 . However, it should be stressed that the antibacterial effect may be dependent on the particle size, the concentration of nanomaterial, its crystal phase, and the mode of activation [ 35 , 38 ]. In the used nanotubes, TiO 2 accounted for 35–45% of the composite.…”

Mass Spectrometric Analysis of Bisphenol A Desorption from Titania Nanoparticles: Ammonium Acetate, Fluoride, Formate, and Hydroxide as Chemical Desorption Agents

“…Particularly, there is mounting evidence that sorption of BPA to microplastic particles led to a reduction of BPA in the aqueous phase and the particles loaded with BPA were ingested by freshwater zooplankton [17]. TiO 2 possesses antibacterial and photocatalytic properties for coating a variety of building, food packaging, and water treatment materials [18,19,20]. TiO 2 polymorphs (anatase, rutile, and brookite) and nanocomposite mixtures are suitable for the catalytic wet air oxidation of BPA [21].…”

Advanced Coatings for Buildings

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