Br-DAPI is a DAPI-derived DNA-binding photosensitizer that produces reactive oxygen species (ROS) upon irradiation, resulting in single/double stranded breaks of bound DNA. Light-induced viability reduction is observed among A549 cells treated with Br-DAPI (IC50 = 1.3 μM; 45 min treatment), but not DAPI (IC50 >64 μM) upon photosensitization (365 nm 15 mW/cm2, 4.5 J/cm2 fluence rate). Its high permeation in both Gram-negative and Gram-positive bacteria allows selective light-induced eradication of bacteria over mammalian cells at low concentration (IC50 = 0.29 μM/N99 E. coli and 0.5 μM/B. subtilis) and light intensity (5 min irradiation by 365 nm LED at 15 mW/cm2, 4.5 J/cm2).

DAPI-derived DNA-binding photosensitizer that allows light-induced cancer cell killing at high concetrations and selective bacteria eradication at low concentrations.