The potential application of a poly(3,4-ethylenedioxythiopene) modified platinum DNA biosensor in mutation analysis

In this study, we have fabricated a label free DNA biosensor by modifying the platinum wire with electrochemically synthesized poly(3,4-ethylenedioxythiopene) and poly(p-aminobenzoic acid). A designed single-strand DNA oligo was immobilized with the carboxyl group of poly(p-aminobenzoic acid) and served as the probe, a target DNA was then hybridized with the probe under a proper condition. Differential pulse voltammetry was performed to characterize the hybridization efficiency in the presence of daunorubicin hydrochloride that was able to be intercalated into the hybridized double-strand DNA and possessed the redox activity. Our results revealed a satisfied linear correlation between the peak current of differential pulse voltammetry and the concentration of complementary target DNA. On the other hand, the mismatches between the target- and probe-DNA caused a significant reduction of electrochemical response, in which was correlated with the amount of mismatched base pairs, therefore the current DNA biosensor had potential applications not only in DNA quantification but also in mutation detection for clinical diagnostics and laboratory applications.