UV light-emitting diodes are an emerging technology and a UV source for pathogen inactivation.
Investigators from Tel Aviv University have demonstrated that the coronavirus disease 2019 (COVID-19) can efficiently and rapidly be killed using ultraviolet (UV) light-emitting diodes (UV-LEDs). UV-LED technology is relatively cheap and can potentially be available soon for both private and commercial use.
"The entire world is currently looking for effective solutions to disinfect the coronavirus," Hadas Mamane, lead author on the study said. "The problem is that in order to disinfect a bus, train, sports hall, or plane by chemical spraying, you need physical manpower, and in order for the spraying to be effective, you have to give the chemical time to act on the surface. Disinfection systems based on LED bulbs, however, can be installed in the ventilation system and air conditioner, for example, and sterilize the air sucked in and then emitted into the room.”
The article, published in the Journal of Photochemistry and Photobiology B: Biology, sought to test which wavelength of light would be the most optimal for killing COVID-19. Investigators conducted the experiment using two UV-LED systems created by AquiSense Technologies. The first system was circular with peak emission wavelengths of 279 nanometers (nm) and 297 nm, with the second system being rectangular with peak emission wavelengths of 267 nm and 286 nm.
Investigators measured the UV spectra of the UV-LED wavelengths using an Ocean Optics USB4000 spectroradiometer equipped with a cosine corrector. The findings demonstrated that a wavelength of 285 nm was almost as efficient in disinfecting the virus as a wavelength of 265 nm, destroying more than 99.9% of the coronavirus in less than half of a minute. 285 nm LED bulbs are much lower in price and are more readily available compared to 265 nm bulbs, making this an important finding.
As the technology develops, hopes are that the bulbs will be installed in robotic systems or air conditioning, vacuum, and water systems, increasing the efficiency of disinfecting large surfaces and spaces.
"We discovered that it is quite simple to kill the coronavirus using LED bulbs that radiate ultraviolet light," Mamane said. "We killed the viruses using cheaper and more readily available LED bulbs, which consume little energy and do not contain mercury like regular bulbs. Our research has commercial and societal implications, given the possibility of using such LED bulbs in all areas of our lives, safely and quickly."