Objectives: Contaminated apparatus and surgical tools pose serious health risks. For such purpose, disinfection chambers are employed. However, these systems rely on mercury-based UV lamps which comes with various drawbacks. These limitations have driven interest in Ultraviolet-C Light Emitting Diode (UV-C LED) technology as a safer and more efficient alternative. However, existing studies have not thoroughly explored the impact of varying intensities of pulse width modulation (PWM) on disinfection efficacy.
Methods: To addess this, the present study designed and tested a LED-based disinfection chamber by employing 4-W 275 nm Surface Mount Device (SMD) LEDs against frequently isolated bacteria. By following prior approach, irradiation time was alternated at 30-s intervals and antibacterial efficacy was assessed through various parameters. Additionally, scanning electron microscopy (SEM) was performed to examine the morphological changes.
Results: Results indicated that the reduction was significantly influenced (p<0.05) with varying PWM levels (60-100 %), achieving 2.05-log10 and 1.54-log10 inactivation against Escherichia coli and Staphylococcus aureus, respectively, upon exposure to 51.24 mJ/cm2 under maximum exposure settings. Moreover, complete cellular damage leading to bleb protrusion and cell-leakage confirmed the disruption of bacterial DNA.
Conclusions: In conclusion, UV-LEDs show great potential for disinfection, with efficiency influenced by PWM and dosage.
Keywords: bacteria; nosocomial infections; pulse width modulation; scanning electron microscopy; ultraviolet-C.
© 2025 the author(s), published by De Gruyter, Berlin/Boston.