Bismuth-rhodamine: a new red light-excitable photosensitizer.

Bismuth-rhodamine (BiR) was developed as a new photosensitizer scaffold, and its photophysical properties were evaluated. BiR showed significant red-shifted absorption and emission compared with other xanthene-based photosensitizers, together with an efficient quantum yield for the generation of 1O2. BiR showed efficient cell-permeability as well as photo-triggered generation of 1O2 in cells.