Patent ID: 7615377

Claim:
A fluorescein-based ligand, comprising a ligand having any one of the following structures: wherein: Ar represents an aryl ring; R is, independently for each occurrence, H, alkyl or aryl; and K is optionally one or more substituents of the indicated aromatic ring, wherein K is independently for each occurrence linear or branched alkyl, alkenyl, linear or branched aminoalkyl, linear or branched acylamino, linear or branched acyloxy, linear or branched alkoxycarbonyl, linear or branched alkoxy, linear or branched alkylaryl, linear or branched hyrdoxyalkyl, linear or branched thioalkyl, acyl, amino, hydroxy, thio, aryloxy, arylalkoxy, hydrogen, alkynyl, halogen, cyano, sulfhydryl, carbamoyl, nitro, trifluoromethyl, amino, thio, lower alkoxy, lower alkylthio, lower alkylamino, nitro, phenoxy, benzyloxy, hydrogen, amine, hydroxyl, alkoxyl, carbonyl, acyl, formyl or sulfonyl.