Novel use of poly(3,4-ethylenedioxythiophene) nanoparticles for fluorescent nucleic acid detection.

In this paper, we demonstrate the novel use of poly(3,4-ethylene dioxythiophene) (PEDOT) nanoparticle as a very effective fluorescent sensing platform for the detection of nucleic acid sequences. The principle of the assay lies in the fact that the adsorption of the fluorescently labeled single-stranded DNA (ssDNA) probe by PEDOT nanoparticle leads to substantial fluorescence quenching, followed by specific hybridization with the complementary region of the target DNA sequence. This results in desorption of the hybridized complex from PEDOT nanoparticle surface and subsequent recovery of fluorescence. A detection limit as low as 30 pM could be achieved in this sensing system. We also demonstrate its application for multiplexed detection of nucleic acid sequences. Furthermore, this sensing system can realize the detection of single-base mismatch even in multiplexed format. It is of importance to note that the successful use of this sensing platform in human blood serum system is also demonstrated.