TiO₂ and N-doped TiO₂ induced photocatalytic inactivation of staphylococcus aureus under 405nm LED blue light irradiation

Irradiation source has been a serious impediment to induce photocatalytic bacterial inactivation which was taken as an advanced indoor air purification technique. Here we reported the synergistic effects of 405nm LED light and TiO₂ photocatalyst in inactivation process of Staphylococcus aureus (S. aureus). In this work, TiO₂ and N-doped TiO₂ particles were, respectively, suspended into the nutrient broth suspension with S. aureus. Then, the mixed system was exposed to a 405nm LED light source with energy density of about 0.2W/cm² for 3 hours. Irradiated suspension was then scanned by UV-vis spectrophotometer for bacteria survive/death rate statistics. Subsequently, the inactivation efficiency was calculated based on the difference of the absorption optical density between experimental and controlled suspensions. Results showed that both TiO₂ and N-doped TiO₂ particles exhibit potential bacterial inactivation effects under similar experimental conditions. Specifically, N-doped TiO₂ with the concentration of 5g/L displayed enhanced inactivation efficiency against S. aureus under 405nm LED light irradiation. Thus, it is a promising indoor air purification technique by using N-doped TiO₂ particles under the LED light irradiation.