Phenylethynylnaphthalene dyes and methods for their use

A method for visually detecting a biomolecule, the method comprising:

• admixing a compound with one or more biomolecules;
• conjugating the compound with the one or more biomolecules;
• and
• detecting the compound conjugated to the one or more biomolecules by its visible properties,
• wherein the compound has the following structure (I):
• or a salt thereof, wherein:
• R1a is -L1-(R3)z-L2-M or -L1-(R3)z-L2-(R3)z-L1—I, where I is, independently, a further compound of structure (I);
• R1b, R1c, R1d, R1e and R1f are each independently H, halo, nitro, C1-C6 alkyl, —SO3−, —SO3alkyl, C1-C6 alkoxy, aryl, aryloxy, C1-C6 alkylcarbonyl, C1-C6 alkylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, amino, alkylamino, arylamino, aralkylamino, -L1-(R3)z-L2-M or -L1-(R3)z-L2—S—S—L2-(R3)z-L1—I, where I is, independently, a further compound of structure (I);
• or one of R1a, R1b, R1c, R1d, R1e or R1f with another one of R1a, R1b, R1c, R1d, R1e or R1f to form a carbocyclic or heterocyclic ring and the remaining R1a, R1b, R1c, R1dR1e and R1f are each independently H, halo, nitro, C1-C6 alkyl, —OSO2−, —OSO2alkyl, C1-C6 alkoxy, aryl, aryloxy, C1-C6 alkylcarbonyl, C1-C6 alkylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, amino, alkylamino, arylamino, or aralkylamino;
• R2a, R2b, R2c, R2d, R2e, R2f, R2g, R2h, R2i and R2j and are each independently H, halo, C1-C6 alkoxy, aryloxy, amino, alkylamino arylamino, aralkylamino, or heterocycle;
• or one or more of R2a, R2b, R2c, R2d, R2e, R2f, R2g, R2h, R2i or R2jjoin with another one or more of R2a, R2b, R2c, R2d, R2e, R2f, R2g, R2h, R2i or R2j on the same ring to form a mono or fused bicyclic carbocyclic or heterocyclic ring and the remaining R2a, R2b, R2c, R2d, R2e, R2f, R2gR2h, R2i and R2j are each independently H, halo, C1-C6 alkoxy, aryloxy, alkylamino, arylamino, aralkylamino, or heterocyclyl;
• R3 is, at each occurrence, independently a mono or bivalent functional group selected from the group consisting of polyalkylether, polyalkylenether, hydroxylalkoxy, hydroxylalkyl, hydroxyalkylene, aminoalkylene, aminoalkoxy, hydroxylpolyalkylether, hydroxylpolyalkylenether, aminopolyalkylether, aminopolyalkylenether, phosphate, thiophosphate, phospho, thiophospho, phosphoalkyl, phosphoalkylene, phosphoalkylether, thiophosphoalkyl, thiophosphoalkylene, thiophosphoalkylether, phosphoramidite and activated phosphorous;
• M is sulfhydryl, disulfide, an activated ester, isothiocyanate, azide, alkyne, alkene, diene, dienophile, acid halide, sulfonyl halide, phosphine, α-haloamide, biotin, amino or a maleimide:
• car M is an analyte molecule or solid support;
• L1 and L2 are, at each occurrence, independently an optional linker;
• x and y are each independently an integer from 0 to 4, and the sum of x and y is 2 or greater;
• and
• z is an integer from 1 to 10.