Quantitative Evaluation of SARS-CoV-2 Inactivation Using a Deep Ultraviolet Light-Emitting Diode

Abstract

Inactivation technology for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is certainly a critical measure to mitigate the spread of coronavirus disease 2019 (COVID-19). A deep ultraviolet light-emitting diode (DUV-LED) would be a promising candidate to inactivate SARS-CoV-2, based on the well-known antiviral effects of DUV on microorganisms and viruses. However, due to variations in the inactivation effects across different viruses, quantitative evaluations of the inactivation profile of SARS-CoV-2 by DUV-LED irradiation need to be performed. In the present study, we quantify the irradiation dose of DUV-LED necessary to inactivate SARS-CoV-2. For this purpose, we determined the culture media suitable for the irradiation of SARS-CoV-2 and optimized the irradiation apparatus using commercially available DUV-LEDs that operate at a center wavelength of 265, 280, or 300 nm. Under these conditions, we successfully analyzed the relationship between SARS-CoV-2 infectivity and the irradiation dose of the DUV-LEDs at each wavelength without irrelevant biological effects. In conclusion, total doses of 1.8 mJ/cm2 for 265 nm, 3.0 mJ/cm2 for 280 nm, and 23 mJ/cm2 for 300 nm are required to inactivate 99.9% of SARS-CoV-2. Our results provide quantitative antiviral effects of DUV irradiation on SARS-CoV-2, serving as basic knowledge of inactivation technologies against SARS-CoV-2.

Marked efficiency enhancement of 222 nm AlGaN-based deep-UV LEDs for disinfection of SARS-2 (Covid-19)

“…It also indicates that the AlN layer has no effect on the peak emission wavelength. It is worth noting that the minute blue shift in LED NIII (0.057 nm) is due to the lowering of quantum confinement stark effect (QCSE) due to lower electrostatic field at the interface of LQB and EBL [8]. The emission spectra of LED B impressively enhanced as compared to LED A.…”

“…In spite of many efforts, the carrier leakage is still a headache for the researcher and the main barrier in the development of efficient UV LEDs, especially DUV LEDs. Inspired by the valuable features, of AlGaN-based DUV (222 nm) recently many researcher reported for the disinfection of SARS-2 (COVID-19) [1,8]. Interestingly, the optoelectronic performance of this specific LED (222 nm) is not satisfactory.…”

Oxidative Inactivation of SARS-CoV-2 on Photoactive AgNPs@TiO2 Ceramic Tiles

“…Under these circumstances and compared with the experiment on glass in the dark, we may confirm that the intensity of UVA radiation at the range of 315-400 nm is not strong enough to deactivate SARS-CoV-2 effectively. Several reports investigated the inactivation of SARS-CoV-2 by direct deep UV irradiation [42][43][44]. Heilingloh et al [45] reported that SARS-CoV-2 was very susceptible to UVC irradiation, while a low inactivation was found under UVA.…”

Not all wavelengths are created equal: disinfection of SARS-CoV-2 using UVC radiation is wavelength-dependent

“…Reports have confirmed the use of UVC LEDs generating around 250-300 nm wavelength to effectively inactivate microorganisms, including bacteria and surrogates [11], viruses and fungi [17]. Although studies agree that shorter wavelengths are more effective at disinfecting coronaviruses [18], there is a dearth of knowledge specifically on effects of wavelengths on SARS-CoV-2 disinfection as relates to dose and irradiation time. Ideally, a test using a consistent set of LED sources at varying wavelengths on actual SARS-CoV-2 should be performed.…”