Review—Electrical Manipulation of DNA Self-Assembled Monolayers: Electrochemical Melting of Surface-Bound DNA

Abstract

DNA provides a powerful framework for the development of biosensors, DNA chips, bioelectronics, and other established and emerging technologies. Many of these applications involve DNA self-assembled monolayers (SAM) on conducting surfaces where the high molecular density, the two-dimensional nature of the interface, and the limited mobility of the strands significantly impact the behavior of the DNA. The unique steric and electrostatic conditions present in the SAM dominate hybridization, melting, and motion of the tethered oligonucleotides. At neutral pH the charged sugar-phosphate backbone makes the DNA sensitive to the electric fields present in the electrical double-layer. Electrode charge provides a means of modifying the reactivity of DNA monolayers; facilitating enhanced rates of hybridization, controlling orientation, and inducing melting (i.e. denaturation). Understanding the effects of electric fields on DNA monolayers is a prerequisite to the optimization of next generation DNA biosensors and other applications that take advantage of DNA’s selective self-assembly. This mini-review will give an overview of the ways in which electrochemical control can be used to manipulate DNA SAMs. In particular, the process of electric field-assisted melting of DNA, i.e. electrochemical melting, will be reviewed. Electrochemical melting has the potential for providing biophysical insights and for the development of new diagnostic applications.