Air discharge plasma used for preventing SARS-CoV-2 infections

The global pandemic caused by SARS-CoV-2 has lasted for more than two years and will still continue, so it is important to develop a new disinfection technology to stop the spread of the virus. Cold atmospheric plasma is well known to have a strong bactericidal effect, and here it is used for the inactivation of pseudoviruses with the SARS-CoV-2 S protein. According to the literature, 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 S protein, and disruption of this process can effectively inhibit SARS-CoV-2 invasion. The plasma is generated by a surface dielectric barrier discharge in air, and two application scenarios are studied: One is for cold chain logistics which is considered as a main route of remote infection, and in that case (-20 ℃) the effluent gas of plasma is used for disinfection. It is found that either dried or the wet pseudovirus are effectively deactivated after exposure to plasma-treated air for 20 min, regardless of whether it is attached to flakes of plastic or a copper sheet. The deactivation effect is much stronger than that treated by the conventional ozone technology. The other is for contact transmission which is frequently happened, and in that case the plasma-activated water (PAW) is used for surface disinfection. It is found that the PAW could effectively inhibited pseudovirus infection through S protein inactivation. The RBD binding activity was inactivated by PAW through the RBD modification. The short-lived reactive species in the PAW, such as ONOO- , played crucial roles in this inactivation. Our findings provide evidence of a potent disinfection strategy to combat the epidemic caused by SARS-CoV-2.