UV-LED lamps generally refer to LEDs with a central wavelength of light emission below 400 nm, but sometimes when the light emission wavelength is greater than 380 nm, it is called a near-ultraviolet LED, and when it is less than 300 nm, it is called a far-ultraviolet LED. Due to the high sterilization effect of short-wavelength light, UV LEDs are often used in biomedical, anti-counterfeiting identification, purification (water, air, etc.) fields, computer data storage, and military.
Based on the characteristics of UV-LED lamps, in the latest study, scientists from the University of Toronto’s Scarborough campus found that the use of UV-LED lamps can destroy the coronavirus and HIV. The lamp can alternate between white light and germicidal ultraviolet (UV) light. With inexpensive retrofits, they can also be used in many standard lighting fixtures, bringing a “unique appeal” to public spaces, said Christina Guzzo, senior author of the study.
The researchers first tested the lamp on bacterial spores (Bacillus pumilus spores), which are known for their resistance to this radiation. “If you can kill these spores, then you can reasonably say that you should be able to kill most other viruses that you routinely encounter in the environment,” the researchers said, showing that within 20 seconds of UV exposure, the spores The growth rate decreased by 99%.
The researchers then created droplets containing the coronavirus or HIV to simulate the typical way people encounter the virus in public, such as from coughing and sneezing. The droplets were then exposed to UV light and placed in culture to see if any virus remained active. After just 30 seconds of exposure, the virus’s ability to infect was reduced by 93 percent.
When testing different concentrations of the virus, they found that samples with more viral particles were more resistant to UV light. But even with this high viral load, infectivity dropped by 88%. In addition, the researchers compared UV light to two heavy-duty disinfectants used in laboratory studies, and they found that the lamps had similar effects in their ability to inactivate viruses.
Of course, while the antibacterial potential of UV-LED lamps in the air has long been established, however, its widespread use in public spaces is limited – broad-spectrum UVC light in the wavelength range between 200 and 400 nanometers (nm) destroys the The molecular bonds that hold DNA together can be very effective at killing bacteria and viruses. This conventional UV light is commonly used to sterilize surgical equipment. But traditional germicidal UV light also harms human health and can cause skin cancer and cataracts, hindering its use in public spaces.
In response, the research team is working with Safe Antivirus Technologies to develop a unique UV-LED lighting module. With motion sensors, the lights automatically switch to UV light when no one is in the room, then switch back to normal light when there is movement.