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 O-1(2). BiR showed efficient cell-permeability as well as photo-triggered generation of O-1(2) in cells.