Detection of DNA oligonucleotides on nanowire array electrodes using chronocoulometry

We present data on the electrochemical detection of DNA oligonucleotides on a three-dimensional array system, and address the problems associated with the miniaturization of the electrode system and the increase in surface area. An anodic aluminum oxide-based template synthesis method is used to fabricate nano-arrays of gold wires. The free-standing wire arrays are then derivatized with a mixed monolayer of thiolated DNA oligonucleotides and mercaptohexanol spacer molecules. A hexamine ruthenium(III) chloride redox marker is used to measure the charge associated with the electrode surface before and after hybridization of complementary target DNA strand. The increase in surface area from a planar gold electrode to our array system requires the use of uncompensated resistance measurements.