Fluorinated TiO2 as an ambient light-activated virucidal surface coating material for the control of human norovirus

• Photocatalytic inactivation of NoVs surrogates (MNV, FCV and MS2) by TiO2 film was investigated.
• Remarkably enhanced oxidative inactivations were demonstrated by adding fluoride ion on TiO2 film.
• Surrogates infectivity declined below the lower detection limit after 12 h office condition irradiation (F/TiO2 system).
• RNA and capsid protein reductions of human norovirus (GII.4) and its surrogate were evaluated after F/TiO2 treatment.

We evaluated the virucidal efficacy of light-activated fluorinated TiO2 surface coatings on human norovirus and several surrogates (bacteriophage MS2, feline calcivirus (FCV), and murine norovirus (MNV)). Inactivation of viruses on surfaces exposed to a common fluorescent lamp was monitored and the effects of UVA intensity, temperature, and fluoride content were assessed. Destruction of RNA and capsid oxidation were evaluated for human norovirus inocula on the F-TiO2 surfaces, while contact with the F-TiO2 surface and exposure to residual UVA radiation of 10 μW cm−2 for 60 min resulted in infectivity reductions for the norovirus surrogates of 2–3 log10. Infectivity reductions on pristine TiO2 surfaces in identical conditions were over 2 orders of magnitude lower. Under realistic room lighting conditions, MS2 infectivity declined below the lower detection limit after 12 h. Reductions in RNA were generally low, with the exception of GII.4, while capsid protein oxidation likely played a larger role in infectivity loss. Inactivation of norovirus surrogates occurred significantly faster on F-TiO2 compared to pristine TiO2 surfaces. The material demonstrated antiviral action against human norovirus surrogates and was shown to effectively inhibit MS2 when exposed to residual UVA present in fluorescent room lighting conditions in a laboratory setting.