Patent ID: 7745377

Claim:
A polypeptide biosensor comprising a polypeptide and a fluorescent dye, wherein said polypeptide is linked by a direct bond or a linking group to said fluorescent dye, and wherein said fluorescent dye on said biosensor comprises a compound of the formula: each m is separately an integer ranging from 1-3; n is an integer ranging from 0 to 5; R 8 , R 11 and R 12 are separately CO, SO 2 , C═C(CN) 2 , S, O or C(CH 3 ) 2 ; each R 13 is hydrogen, alkyl, branched alkyl or heterocyclic ring derivatized with charged groups to enhance water solubility and enhance photostability; each R 9 and R 10 is separately hydrogen, an alkyl chain derivatized with charged groups to enhance water solubility or with reactive groups for conjugation to other molecules.