Water-solubilisation and bio-conjugation of a red-emitting BODIPY marker.

The synthesis and preliminary bio-conjugation studies of a novel water-soluble red-emitting di-styryl BODIPY dye are disclosed. Aggregation behaviour of this compound under physiological conditions was suppressed by specific introduction of a di-sulfonated peptide-based linker at the meso phenyl substituent, sultonated styryl arms and short polyethyleneglycol chains at the boron center. Thus, a good quantum yield of 22% in PBS for this red-emitting BODIPY was obtained. Introduction of an activated ester function enabled successful bio-conjugation to monoclonal antibodies and proteins.