Could UV-LEDs play a role in the fight against COVID-19?

For the first time, scientists have studied the disinfection efficiency of ultraviolet light-emitting diode irradiation at different wavelengths or frequencies on a virus from the coronavirus family. Published in the Journal of Photochemistry and Photobiology B: Biology, the research suggests that this technology could be installed in air conditioning and water systems to eliminate coronaviruses, like the one responsible for covid-19.

"The entire world is currently looking for effective solutions to disinfect the coronavirus. 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," explains professor Hadas Mamane, the study's lead author.

The researchers tested different wavelengths to determine which would be the best for killing the coronavirus. They found that a length of 285 nanometers (nm) was almost as efficient in disinfecting the virus as a wavelength of 265 nm, requiring less than 30 seconds to destroy more than 99.9% of the coronaviruses. This result is significant because the cost of 285 nm LED bulbs is much lower than that of 265 nm bulbs, and the former are also more readily available.

"We discovered that it is quite simple to kill the coronavirus using LED bulbs that radiate ultraviolet light," she explained. "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," concludes Hadas Mamane.