Ultraviolet light-emitting diodes inactivate microorganisms on contaminated surface

Abstract

Ultraviolet light emitting diode (UV-LED) is a hygienic treatment in effectively inactivating pathogenic microorganisms on surfaces and objects. However, how the combination types of different light influence the disinfection efficiency remains elusive. In this study, the effects of single and double wavelength on surface disinfection were assessed. Meanwhile, the effects of different radiation modes on surface disinfection were studied. The results showed that the dual-wavelength (UVA and UVC) had better disinfecting effect than the single wavelength. For the irradiation mode, UVA pre-treatment enhanced the inactivation effectiveness of microorganisms on surface. In detail, 367 nm UVA pre-treatment followed by 265 nm UVC worked better as the log inactivation of the dual-wavelength was more than 2 times higher than that from the sum of applying single exposure separately. Moreover, the radiational order had a significant impact on disinfection effect. In addition, extending the irradiation time could enhance the inactivation efficiency. In summary, this study provides a new insight into the development of surface disinfection technologies.