The aim of this work was to study the photocatalytic activity of titanium dioxide (TiO2) against Listeria
monocytogenes bacterial biofilm. Different TiO2 nanostructured thin films were deposited on surfaces
such as stainless steel and glass using the doctor-blade technique. All the surfaces were placed in test
tubes containing Brain Heart (BH) broth and inoculated with L. monocytogenes. Test tubes were then
incubated for 10 days at 16 C in order to allow biofilm development. After biofilm formation, the
surfaces were illuminated by ultraviolet A light (UVA; wavelength of 315e400 nm). The quantification of
biofilms was performed using the bead vortexing method, followed by agar plating and/or by conductance
measurements (via the metabolic activity of biofilm cells). The presence of the TiO2 nanoparticles
resulted in a fastest log-reduction of bacterial biofilm compared to the control test. The biofilm of
L. monocytogenes for the glass nanoparticle 1 (glass surface modified by 16% w/v TiO2) was found to have
decreased by 3 log CFU/cm2 after 90 min irradiation by UVA. The use of TiO2 nanostructured photocatalysts
as alternative means of disinfecting contaminated surfaces presents an intriguing case, which
by further development may provide potent disinfecting solutions. Surface modification using nanostructured
titania and UV irradiation is an innovative combination to enhance food safety and economizing
time and money.