Selenadiazoloquinolone E2h is a new potent photosensitizer.
E2h inhibited the growth of HeLa cells and induced S and G2/M arrest and apoptosis.
UVA irradiation (dose 0.359 J cm− 2) increased derivative cytotoxicity.
Changes in ROS level, mitochondrial potential and caspase 3 activity were found.