Homogeneous fluorescence-based DNA detection with water-soluble conjugated polymers

Methods for real-time, high-sensitivity polynucleotide detection are of vast scientific and economic importance. Homogeneous biosensor assays that take advantage of the collective response of water-soluble conjugated polymers and the self-assembly characteristic of aqueous polyelectrolytes have shown potential for improvements over small molecule methods. Cationic polythiophenes transduce oligonucleotide hybridization into a colorimetric output based on conformational changes of the polymer upon interaction with single-stranded DNAs or double-stranded DNAs. Cationic poly(fluorene-co-phenylene) materials serve as donors in fluorescence energy-transfer assays which display signal amplification. Signal transduction in aqueous media is controlled by specific electrostatic interactions.