The Bactericidal Efficacy of a Photocatalytic TiO<sub>2</sub> Particle Mixture with Oxidizer against <i>Staphylococcus aureus</i>

Abstract

By proving the bactericidal effects of a low-concentration titanium dioxide (TiO2) particle mixture against Staphylococcus aureus, we hope to ultimately apply a mixture of this type as part of a clinical treatment regimen. A bacterial suspension of S. aureus 1×105 CFU/ml was added dropwise to a TiO2 particle mixture (19 ppm TiO2) and irradiated by ultraviolet (UV) light. The colony-forming units were counted and the bacterial survival rate was calculated. In the control sample, the bacterial survival rate was 83.3% even after 120 min. In the TiO2 mixture + UV sample, the bacteria count dropped sharply, reaching 17.3% of the baseline value at 30 min and 0.4% at 60 min. TiO2 particles dispersed in water mixtures are known to elicit highly efficient UV absorption and greater bonding to bacteria. A reaction of the TiO2 with another oxidizer altered the aqueous pH and accelerated the photocatalytic chemical reaction. The TiO2 particle mixture showed high antibacterial action against S. aureus even at a low concentration.