DNA Electrochemical Hybridization Detection in Droplets Using Gold Ultramicroelectrodes in a Two-Electrode Configuration

摘要

A 23-base DNA probe monolayer was self-assembled on a 25-μm gold microelectrode via thiol adsorption. Long-range electron transfer and the use of the redox methylene blue as DNA intercalator were chosen for the monitoring of the hybridization step. The electrochemical properties of the sensor were screened with the [Fe(Ⅲ)(CN)_6]~(3-)/[Fe(Ⅱ)(CN)_6]~(4-) redox couple in cyclic voltammetry in a two-electrode configuration well adapted in the case of microliter biological samples. A study of the stability of the self-assembled monolayer is included in this work. The femtomolar limit of detection for DNA target quantification was deduced from the current density measured and blank measurements depicting the desorption rate of the thiolated DNA probes.