Inactivation of Human Coronavirus (SARS-CoV-2) By Titania Nanoparticle Coatings and UVC Radiation

The novel pathogenic human coronavirus, SARS-CoV-2, led to an atypical pneumonia-like severe acute respiratory syndrome (SARS) outbreak called coronavirus disease 2019 (abbreviated as COVID-19). Nearly, 77 million cases have been confirmed worldwide with the highest COVID-19 cases been confirmed in the United States. Substantial efforts to create a potential vaccine to combat COVID-19 are underway. In the meantime, safety precautions and effective disease control strategies appear to be vital for preventing the virus spread in the public places. Due to the longevity of the virus on smooth surfaces, photocatalytic properties of “self-disinfecting/cleaning” surfaces appear to be a promising tool to help guide disinfection policies to control infectious SAR-CoV-2 spread in high-traffic areas such as hospitals, grocery stores, airports, schools, and stadiums. The photocatalytic properties of nanosized TiO 2 (TNPs) as induced by the UV radiation, towards virus deactivation have been explored in this study. The preliminary results using close genetic relative of SAR-CoV-2, HCoV-NL63, showed the virucidal efficacy of photoactive TNPs deposited on glass coverslips, as examined by quantitative RT-qPCR and virus culture assays. The photocatalytic inactivation performance of TNPs was evaluated under different light intensities, humidic conditions, and UV-exposure time. The findings form the basis for the application of an electrical bias on the TiO 2 electrodes towards removal and inactivation of the virus. Efforts to extrapolate the underlying concepts described in this study to SARS-CoV-2 are currently underway.