An ultrasensitive label-free biosensor for assaying of sequence-specific DNA-binding protein based on amplifying fluorescent conjugated polymer

► Ultrasensitive detection of sequence-specific DNA-binding protein with label-free oligonucleotide. ► High efficient FRET from the cationic conjugated polymer to intercalating dye. ► Excellent reproducible and quantitative analysis of NF-кB using fluorometric and colorimetric methods.