Investigation of Plasma-generated Reactive Species Responsible for Human Coronavirus Inactivation

The recent global pandemic of Corona Virus Disease-19 (COVID-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, infectivities of human coronavirus 229E (HCoV-229E) after various APP treatments were evaluated. Exposure of HCoV-229E solution to a helium (He) APP for 30 s significantly reduced the HCoV-229E virus titers (3 log₁₀TCID₅₀ reduction). This shows a powerful virus-inactivation efficacy of the APP. The experiments with the H₂O₂/NO₂⁻supplement and the 5 types of RONS scavengers indicated that O₂^•− and/or O₂^•−-derived species can be important for the APP-induced virus inactivation while other short-lived RONS (^•OH, ¹O₂, ^•NO) and long-lived RONS (H₂O₂, NO₂⁻, NO₃⁻) could not contribute, specifically even though very high-rate of ^•OH production (~1.7 nmol/s). In the presentation, separate contribution of reactive species generated by various APP devices will be discussed.