Electrochemically Induced Release of DNA from Gold Ultramicroelectrodes

Abstract

Cathodic desorption is used for inducing the release of single and double-stranded DNA layers from gold microelectrodes (12.5 μm radius). The desorption behavior has been characterized by electrochemical quartz microbalance (EQCM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) “blocking” experiments. These studies indicate an effective removal of the assembled nucleic acids from the surface to solutions of physiological pH and shed useful insights into the confinement of relatively long (350bp) segments of dsDNA on gold surfaces. The effect of various parameters influencing the release of the attached DNA, including the desorption potential and time, has been examined, with 2−5 min at −1.30 V (vs Ag/AgCl) sufficient for a complete removal. The time scale for the desorption of nucleic acids is shorter than that of alkanethiol monolayers. Such an on-demand electrochemical release of DNA holds great promise for delivering small amounts of the genetic material to specific locations at ap...