Reagents for directed biomarker signal amplification

An assay method for detecting a target biomolecule in a sample comprising:

• providing a sample that is suspected of containing a target biomolecule;
• providing a conjugated polymer complex comprising sensor biomolecule conjugated to a water soluble conjugated polymer having the structure of Formula (Ia):
• wherein:
• each R is independently a side group capable of imparting solubility in water;
• MU is a polymer modifying unit or band gap modifying unit that is evenly or randomly distributed along the polymer main chain and is optionally substituted with one or more optionally substituted substituents selected from halogen, hydroxyl, C1-C12 alkyl, C2-C12 alkene, C2-C12 alkyne, C3-C12 cycloalkyl, C1-C12 haloalkyl, C1-C12 alkoxy, C2-C18 (hetero)aryloxy, C2-C18 (hetero)arylamino, (CH2)x′(OCH2CH2)yOCH3 where each x′ is independently an integer from 0-20, y′ is independently an integer from 0 to 50, or a C2-C18 (hetero)aryl group;
• each optional linker L1 and L2 are aryl or hetroaryl groups evenly or randomly distributed along the polymer main chain and are substituted with one or more pendant chains terminated with a functional group selected from amine, carbamate, carboxylic acid, carboxylate, maleimide, activated esters, N-hydroxysuccinimidyl, hydrazines, hydrazids, hydrazones, azide, alkyne, aldehydes, thiols, and protected groups thereof for conjugation to another substrate, molecule or biomolecule;
• G1 and G2 are each independently selected from hydrogen, halogen, alkyne, optionally substituted aryl, optionally substituted heteroaryl, halogen substituted aryl, boronic acid substituted aryl, boronic ester substituted aryl, boronic esters, boronic acids, optionally substituted fluorine and aryl or hetroaryl substituted with one or more pendant chains terminated with a functional group, molecule or biomolecule selected from amine, carbamate, carboxylic acid, carboxylate, maleimide, activated esters, N-hydroxysuccinimidyl, hydrazines, hydrazids, hydrazones, azide, alkyne, aldehydes, thiols, and protected groups thereof for conjugation to another substrate, molecule or biomolecule;
• wherein the polymer comprises at least 1 functional group selected from amine, carbamate, carboxylic acid, carboxylate, maleimide, activated esters, N-hydroxysuccinimidyl, hydrazines, hydrazids, hydrazones, azide, alkyne, aldehydes, and thiols within G1, G2, L1 or L2 that allows, for functional conjugation to another molecule, substrate or biomolecule;
• n is an integer from 1 to about 10,000;
• and
• a, b, c and d define the mol % of each unit within the structure which each can be evenly or randomly repeated and where a is a mol % from 10 to 100%, b is a mol % from 0 to 90%, and each c and d are mol % from 0 to 25%;
• wherein the sensor biomolecule is capable of interacting with the target biomolecule or a target-associated biomolecule and wherein the polymer is optionally conjugated to a signaling chromophore;
• contacting the sample with the sensor biomolecule and the conjugated polymer in a solution under conditions in which the sensor biomolecule can bind to the target biomolecule or a target-associated biomolecule if present;
• applying a light source to the sample that can excite the polymer;
• and detecting whether light is emitted from the conjugated polymer complex.