Comparative multivariate analysis for high-touch surface disinfection using optimized ultraviolet-C LEDs configuration

Abstract

UV light-emitting diodes (LEDs) have been regarded as feasible alternatives for traditional UV lamps since the early 2000s, owing to their improved safety features, environmental advantages, and efficiency. Because of the inherent challenges associated with lower intensity of LEDs over extended distances, our findings demonstrated the optimized disinfection efficiency using various LED setups. This study evaluated the antimicrobial effectiveness of single, six, and eight-LED configurations against Staphylococcus aureus (S. aureus), specifically emphasizing attaining the utmost disinfection efficiency within an extended range of up to 60 cm. With an 8-LED configuration, the study achieved a substantial reduction of 6.10×10⁴ CFU/mL from an initial level of 5.20×10⁹ CFU/mL, corresponding to 4.9-log₁₀ inactivation, requiring a dose of 264 µJ-cm⁻². 2.9-log₁₀ inactivation was achieved using a 6-LED, yielding lower yet comparable efficiency requiring 192 µJ-cm⁻² of dose. However, with 60 µJ-cm⁻² of dose, a single LED could only reduce the bacterial burden from the initial level to merely 0.2-log₁₀ inactivation, corresponding to 2.9 × 10⁹ CFU/mL, under similar exposure settings. In conclusion, UV-LEDs show promise for disinfection, with LED configuration and distance significantly impacting their efficiency, holding perspective for various applications, particularly within healthcare facilities.