UV-LED disinfection of Coronavirus: Wavelength effect

Abstract

UV light-emitting diodes (UV LEDs) are an emerging technology and a UV source for pathogen inactivation, however low UV-LED wavelengths are still expensive and of low fluence. Our results suggest that the sensitivity of human Coronavirus (HCoV-OC43 used as SARS-CoV-2 surrogate) was wavelength dependent with 267 nm ~ 279 nm > 286 nm > 297 nm. Other viruses showed similar results, suggesting UV LED with peak emission at ~286 nm could serve as an effective tool in the fight against human Coronaviruses.

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

“…In the current global pandemic of SARS-CoV-2, means to inactivate viruses and prevent infections must be taken. DUV irradiation is one powerful and effective way to combat various microorganisms including SARS-CoV-2 and related coronaviruses [10][11][12][13][14][15][16][17]. However, in order to establish commonly and widely usable inactivation apparatuses/techniques using DUV, reliable quanti ed data that can serve as a solid standard for their development are required; the length of the DUV irradiation periods, which wavelength, and what doses of DUV are needed for SARS-CoV-2 inactivation.…”

“…While the biological effects of DUV light have been widely proven across different types of viruses [14,[16][17][18][27][28][29][30][31], the precise mechanism by which the DUV light inactivates viruses remains to be elucidated [18]. Several studies reported that virus inactivation by DUV irradiation is primarily caused by the photochemical reactions of nucleic acids [18,32,33].…”

“…Thermal treatment is also known to be effective for SARS-CoV-2 inactivation [8,9]. Photochemical inactivation, especially using deep ultraviolet (DUV) light (λ < 300 nm), is the most time-saving and e cient way to inactivate SARS-CoV-2 and related coronaviruses [10][11][12][13][14][15][16][17]. DUV light irradiation exerts a critical effect on the infectivity of microorganisms and viruses probably by damaging their RNAs [18].…”

SARS-CoV-2 in the environment—Non-droplet spreading routes

“…The advantage of UV LED is their small size, low voltage requirement, and the possibility of configuration for many wavelengths in the UV spectrum. Low-wavelength UV LEDs, however, are costly and have a low fluence rate ( Gerchman et al, 2020 ). UV LED, and DUV LED (deep ultraviolet light-emitting diode) showed high effectivity against HCoV-OC43 and SARS-CoV-2, respectively ( Table 7 ).…”

Inactivating SARS-CoV-2 Using 275nm UV-C LEDs through a Spherical Irradiation Box: Design, Characterization and Validation

“…Optical design From recent scientific literature, the amount of fluence necessary to inactivate the Sars-CoV-2 is estimated at different values approximately between 6-8 mJ/cm 2 [14], up to 37.5 mJ/cm 2 [15] Our aim is to inactivate the virus in few minutes, possibly just 60 seconds. We set the ideal average irradiance at 2.5 W/m 2 and a target minimum irradiance of 1 W/m 2 .…”