An electropolymerized membrane biosensor for specific DNA recognition

dA sensitive electrochemical biosensor for detecting the sequence of short DNA oligomers is represented. The biosensor is based on a platinum electrode covered a polymerized membrane of conductive monomer N-[6-(thien-3-yl)acetoxy]-pyrrolidine-2, 5-dione (TAPD). The membrane of TAPD immobilizes a probe DNA on the electrode. The hybridization of the probe with a sequence-specific DNA in sample solutions is monitored by a self-synthesized electroactive indicator, which specifically intercalates in the hybrids on the electrode surface. The current signal of the biosensor is proportional to the concentration of the target DNA in samples, and a very low detection limit of 5 x 10(-10) mol/L is found. The biosensor has been used to detect the short oligomers containing of HIV-1 and mycobacterrium nucleotide sequences.