Electrochemical detection of a dengue-related oligonucleotide sequence using ferrocenium as a hybridization indicator

Abstract

A simple method for electrochemical detection of a synthetic 20-bp oligonucleotide sequence related with dengue virus genome was developed. A complimentary DNA probe sequence was electrostatically immobilized onto a glassy carbon electrode modified with chitosan. Electrochemical detection of hybridization between probe and target was performed by cyclic voltammetry, using ferrocene (Fc+) as a hybridization label. After hybridization, the peak current response of Fc+ oxidation increased around 26%. A higher voltammetric decay rate constant (ka) and a lower half-life period (t1/2) for the interaction of Fc+ with dsDNA compared to those with ssDNA quantitatively characterize the different strengths of interaction with both types of DNA. By combining the simplicity of DNA immobilization onto a chitosan film and suitable voltammetric detection of hybridization concomitant with ferrocene attachment, a good discrimination between ssDNA and dsDNA was obtained. © 2007 by MDPI.