Fluorescent methods and materials for directed biomarker signal amplification

A multichromophore complex for identifying a target cell protein comprising:

• a multichromophore comprising a water-soluble, light harvesting π conjugated polymer comprising substituted or unsubstituted multiple units in a π conjugated state wherein each unit has the structure:
• and a linker having a bioconjugation site,
• an antibody covalently linked to the multichromophore by the bioconjugation site on the linker of the π conjugated polymer,
• an optional signaling chromophore covalently bound to the multichromophore or covalently bound to the antibody,
• wherein
• the optional signaling chromophore is capable of receiving energy from the multichromophore upon excitation of the multichromophore and
• wherein the antibody is capable of recognizing cells with the target cell protein expressed and specifically bind to the protein,
• wherein A is independently an aromatic, heteroaromatic, optionally substituted conjugated polymer segment or oligomeric structure, and where at least one A is a phenyl linked to the linker,
• wherein R1 is a water solubilizing group,
• wherein * is a site for π conjugation and
• wherein said water solubilizing group is elected from the group consisting of ethylene glycol oligomers, ethylene glycol polymers, ω-ammonium alkyl salts, ω-ammonium alkoxy salts, ω-ammonium oligoether salts, ω-sulfonate alkyl salts, ω-sulfonate alkoxy salts, and ω-sulfonate oligoether salts and combinations thereof.