However, among the many chemical structures reported to date, very few photosensitizers can utilize endogenous metabolic transporters. Herein we describe benzoselenadiazoles as a generic photosensitizer scaffold to produce phototoxic metabolites. The synthesis of aminobenzoselenadiazoles from small metabolites is straightforward, with high-yielding and scalable reactions (Figure ). Given that many metabolites contain reactive amino groups (e.g., amino acids, aminoglycans, peptides), this chemical strategy is translatable to a broad range of biological transporters and cell types.