Photo-catalyzed TiO2 inactivates pathogenic viruses by attacking viral genome

[Display omitted] •A system to study the antiviral effect of nanosized TiO2 at low irradiation is developed.•·OH produced by photo-activated TiO2 is the main effector to attack viral RNA genome.•Nanosized TiO2 illuminated by indoor light can disinfect pathogens.•Photo-activated TiO2 inactivates a broad range of pathogens including SARS-CoV-2. Previous observations have been reported that viruses were inactivated using strong irradiation. Here, new evidence was disclosed by studying the effects of nanosized TiO2 on viral pathogens under a low irradiation condition (0.4 mW/cm2 at UVA band) that mimics the field setting. We showed that photo-activated TiO2 efficiently inhibits hepatitis C virus infection, and weak indoor light with intensity of 0.6 mW/cm2 at broad-spectrum wavelength and around 0.15 mW/cm2 of UVA band also lead to partial inhibition. Mechanistic studies demonstrated that hydroxyl radicals produced by photo-activated TiO2 do not destroy virion structure and contents, but attack viral RNA genome, thus inactivating the virus. Furthermore, we showed that photo-activated TiO2 inactivates a broad range of human viral pathogens, including SARS-CoV-2, a novel coronavirus responsible for the ongoing COVID-19 pandemic. In conclusion, we showed that photo-catalyzed nanosized TiO2 inactivates pathogenic viruses, paving a way to its field application in control of viral infectious diseases.