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

Abstract

We report on the design, characterization and validation of a spherical irradiation system for inactivating SARS-CoV-2, based on UV-C 275 nm LEDs. The system is designed to maximize irradiation intensity and uniformity and can be used for irradiating a volume of 18 L. To this aim: (i) several commercially available LEDs have been acquired and analyzed; (ii) a complete optical study has been carried out in order to optimize the efficacy of the system; (iii) the resulting prototype has been characterized optically and tested for the inactivation of SARS-CoV-2 for different exposure times, doses and surface types; iv) the result achieved and the efficacy of the prototype have been compared with similar devices based on different technologies. Results indicate that a 99.9% inactivation can be reached after 1 min of treatment with a dose of 83.1 J/m2.

Defects and Reliability of GaN‐Based LEDs: Review and Perspectives

“…Regarding this latter market segment, researchers and industries are also pushing toward the development and adoption of displays based on blue and green micro-LEDs, [1][2][3] which are set to become the standard for high-contrast future displays for mobile and home entertainment. Moving toward the UV range, down to 260 nm, AlGaN-based solid-state emitters are becoming of utmost interest because they allow the fabrication of low-cost and efficient sanitation equipment for objects and surfaces, [4,5] for the purification of waste waters, [6,7] for bioagent detection, [8] and for curing applications. [9] Finally, visible LEDs are also becoming of interest for optical communications based on standard solid-state luminaires, which can allow direct free-space data transfer rates in excess of 1 Gb s À1 .…”

UV-Based Technologies for SARS-CoV2 Inactivation: Status and Perspectives

“…Figure 11. SARS-CoV-2 reduction as a function of the irradiation dose for UVC LEDs with a peak wavelength of 280 nm ± 5 nm, some of the results are verified on different carrier materials [19,46,68,69,72,73].…”

“…Trivellin et al [73] designed a sanitization system based on 280 nm LEDs and specifically designed to inactivate SARS-CoV-2 on spherical objects, like sport balls, a total of 56 LEDs each emitting 10 mW has been used on a spherical surface of 25 mm of diameter. The result achieved indicate that a 99.9% inactivation can be reached after 1 min of treatment with a dose of 83.1 J/m 2 independently on the types of material and its size.…”

Evaluation of Virucidal Efficacy of Human Norovirus Using Combined Sprayed Slightly Acidic Electrolyzed Water and Ultraviolet C-Light-Emitting Diode Irradiation Treatment Based on Optimized Capture Assay for Quantitative RT-qPCR

“…Particularly, the virucidal efficacy of UVC-LED against human enteric virus surrogates was significantly inactivated by up to 7 log 10 following treatment with 1 mJ/cm 2 for ΦX 174 and 9 mJ/cm 2 for Qβ and MS2 ( Kim et al, 2017 ). For UVC-LED disinfection of SARS-CoV-2 on a rubber surface, Trivellin et al (2021) study the design, characterization, and validation of UVC-LED disinfection and demonstrate that a 3 log 10 reduction could be achieved following 60 s of irradiation with a 8.31 mJ/cm 2 dose. Although UVC-LED disinfection can effectively inactivate infectious viruses, the shortcoming of UV irradiation is that there is no durative antimicrobial activity because the DNA damage of the microbial cells caused by UV irradiation can be repaired through photoreactivation or nucleotide excision repair.…”