Enhanced viral inactivation by combined ultraviolet light and heat

Abstract

Viral sensitivity to high temperature and ultraviolet (UV) irradiation has been extensively studied. However, there is still little attention paid to study the joint effect of these two physical factors. Since the outbreak of the COVID-19 pandemic has necessitated the advances of disinfection techniques, rapid and effective viral inactivation by combining heat and UV light is worth investigating. This work focuses on developing such a device combining UV light-emitting diode light sources and a heater. Moreover, two UV bands have been studied in this work, namely 280 nm ultraviolet-C (UVC) and 365 nm ultraviolet-A (UVA. A) control system is developed to accurately control both the heating temperature of the device and the irradiance of the dual-spectral UV light sources. The performance of the device is verified by a series of experimental measurements. More importantly, the disinfection effect of the device has been verified by the experiments based on non-pathogenic carrier virus commonly used in the laboratory. The disinfection doses of the 280 nm UVC and 365 nm UVA light sources under the high temperature synergy have been examined. The experimental results show that when combined with a heating temperature of 60 ∘C, the cumulative UV radiation doses required for sufficient viral inactivation can be greatly reduced.