Human coronavirus inactivation by atmospheric pressure helium plasma

Abstract

The recent global pandemic of Corona Virus Disease-19 has impacted all aspects of society, producing a growing demand for a powerful virus inactivation method. To assess a potential and mechanism of human coronavirus inactivation using atmospheric pressure plasma (APP) technology, replication of a human coronavirus (HCoV-229E) after He + H2O APP plume exposure was evaluated using rhesus monkey kidney epithelial cells. The HCoV-229E titers were reduced by 3 log10TCID50 after the APP exposure for 30 s, showing a strong virus-inactivation efficacy of the APP. It was experimentally verified that the APP produced the liquid-phase reactive oxygen and nitrogen species (RONS) at high rates [e.g. •OH: ∼1.7 nmol s−1, H2O2 (including H2O2 precursors): ∼9.2 nmol s−1, NO2 − (including NO2 − precursors): ∼3.3 nmol s−1]. However, an administration of H2O2 with NO2 − failed to inactivate the virus and only Mn type superoxide dismutase among several RONS scavengers for •OH, HO2 •/O2 •−, 1O2, and •NO/•NO2 was significantly effective for the recovery of the APP-induced decrease in the viral titers. This suggests O2 •−-related chemical reaction in a network of interconnected reactions induced by the APP exposure is very important for the APP-induced virus inactivation. These results provide new insight into a more efficient inactivation method of human coronavirus using APPs.