Elimination Voltammetry with Linear Scan as a New Detection Method for DNA Sensors

The paper describes successful coupling of adsorptive transfer stripping (AdTS) and elimination voltammetry with linear scan (EVLS) for the resolution of reduction signals of cytosine (C) and adenine (A) residues in hetero-oligodeoxynucleotides (ODNs). Short ODNs (9-mers and 20-mers) were adsorbed from a small volume on a hanging mercury drop electrode (HMDE). After washing of the ODN-modified electrode by water and its transferring to an electrochemical cell, voltammetric Sensors 2005, 5 449 curves were measured. The AdTS EVLS was able to determine of C/A ratio of ODNs through the elimination function conserving the diffusion current component and eliminating kinetic and charging current components. This function, which provides the elimination signal in a peak-counterpeak form, increased the current sensitivity for A and C resolution, and for the recognition of bases sequences in ODN chains. Optimal conditions of elimination experiments such as pH, time of adsorption, and scan rate were found. The combination of EVLS with AdTS procedure can be considered as a new detection method in a DNA sensor.