Virucidal action of photogenerated pink phenothiazine radical cation impregnated in cotton fabric and polypropylene face mask

Abstract

The COVID-19 pandemic increased the interest in the development of self-disinfecting materials. In this innovative study, cotton and polypropylene fabrics impregnated with the photochemically generated 10H-phenothiazine (PHT) radical cation (PHT•+) gained highly effective virucidal properties. The effectiveness of PHT•+ adsorption was demonstrated by advanced analytical techniques, including electron paramagnetic resonance (EPR), UV–visible, and FT-Raman spectroscopies that confirmed the presence of PHT•+ in the fabrics, even after washing and a re-exposure to light. Colorimetric test evidenced PHT•+ in the cotton fabric even after 2 months in the dark. Viral inactivation assays were performed with the fabrics treated with PHT. Results of qPCR showed that fabrics impregnated with PHT•+ were highly effective at reducing the viral genome compared to untreated fabrics. PHT•+ destroys the virus by an oxidative attack on the viral envelope, evidenced by the quenching of the EPR signal of fabrics exposed to a model of the virus envelope. Also, cryo-transmission electron microscopy captured stunning images of virus destruction caused by the oxidative attack of PHT•+ on the virus envelope. Overall, this study represents a significant advance in developing self-disinfecting materials and could have far-reaching implications for the fight against viral infections.