A poly (diallyldimethylammonium chloride)-mediated R-phycoerythrin/DNA hybrid system as a fluorescent biosensor for DNA detection

Abstract

A simple, fast, fluorescent biosensor for DNA detection was developed based on a poly (diallyldimethylammonium chloride) (PDADMAC) -mediated R-phycoerythrin (R-PE) /DNA hybrid system. In the presence of PDADMAC, R-PE can efficiently absorb BHQ2-labeled single-stranded DNA (BHQ2-ssDNA) form stable R-PE/ssDNA complex and its fluorescence is significantly quenched by the labeled BHQ2 of the ssDNA through fluorescence resonance energy transfer (FRET) between R-PE and BHQ2. Upon the addition of complementary target DNA, BHQ2-ssDNA was released from the R-PE surface due to the formation of rigid double-strand DNA and the fluorescence of R-PE, correspondingly, is recovered. The proposed fluorescent biosensor presents high selectivity and sensitivity with a detection limit of 0.17 nM. This approach provides a promising platform for nucleic acid detection and molecular sensing.