Plasma-activated water: An alternative disinfectant for S protein inactivation to prevent SARS-CoV-2 infection

SARS-CoV-2 is a highly contagious virus and is causing a global pandemic. SARS-CoV-2 infection depends on the recognition of and binding to the cellular receptor human angiotensin-converting enzyme 2 (hACE2) through the receptor-binding domain (RBD) of the spike protein, and disruption of this process can effectively inhibit SARS-CoV-2 invasion. Plasma-activated water efficiently inactivates bacteria and bacteriophages by causing damage to biological macromolecules, but its effect on coronavirus has not been reported. In this study, pseudoviruses with the SARS-CoV-2 S protein were used as a model, and plasma-activated water (PAW) effectively inhibited pseudovirus infection through S protein inactivation. The RBD was used to study the molecular details, and the RBD binding activity was inactivated by plasma-activated water through the RBD modification. The short-lived reactive species in the PAW, such as ONOO⁻, played crucial roles in this inactivation. Plasma-activated water after room-temperature storage of 30 days remained capable of significantly reducing the RBD binding with hACE2. Together, our findings provide evidence of a potent disinfection strategy to combat the epidemic caused by SARS-CoV-2.