Patent ID: 7811755

Claim:
An assay method comprising: providing a sample that is suspected of containing a target polynucleotide; providing a polycationic multichromophore that comprises a conjugated polymer, wherein said polymer comprises a plurality of low bandgap repeat units sufficient for the polymer to form an excited state when the polymer is contacted with incident light in the region of about 450 nm to about 1000 nm in the absence of the target biomolecule has a detectable excitation emission when excited with light comprising a wavelength in the region of about 450 nm to about 1000 nm; providing a sensor that is a polynucleotide that is complementary to the target polynucleotide, wherein said sensor is conjugated to a substrate and is not chemically conjugated to a fluorescently detectable label that can receive energy from an excited state of the multichromophore, wherein the target is chemically attached to a fluorescently detectable label that can receive energy from an excited state of the multichromophore; contacting the substrate with the sample; contacting the substrate with the multichromophore under conditions wherein the multichromophore can bind to the sensor and/or target polynucleotide, if present; and detecting whether target has bound to the sensor by detecting whether energy has been transferred from the multichromophore.