Flexible organic light-emitting diodes for antimicrobial photodynamic therapy

Abstract

Bacterial infection is a serious and growing problem as antibiotic resistance grows leading to patient suffering, death and increased costs of healthcare. To address this problem, we propose using flexible organic light-emitting diodes (OLEDs) as light sources for photodynamic therapy (PDT) to kill bacteria. PDT involves the use of light and a photosensitizer to generate reactive oxygen species that kill neighbouring cells. We have developed flexible top-emitting flexible OLEDs with the ability to tune the emission peak from 669-737 nm to match the photosensitizer, together with high irradiance, low driving voltage, long operational lifetime and adequate shelflife. These features enable OLEDs to be the ideal candidate for ambulatory PDT light sources. A detailed study of OLED-PDT for killing S. aureus was performed. The results show that our OLEDs in combination with the photosensitizer methylene blue can kill more than 99% of bacteria, which indicates a huge potential for using OLEDs to treat bacterial infections.