Controlling a Single DNA Molecule in an Electric Field by Means of In Situ Atomic Force Microscopy

DNA is the bio-polymer containing the genetic information needed for the development and functioning for all living organisms. It has a polymeric structure consisting of units called nucleotides, each consisting of a non-polar, hydrophobic interior (the base pairs) and polar, hydrophilic exterior which is negatively charged due to the phosphate groups along the backbone of the DNA. Its heterogeneous properties permit DNA molecule to interact with other molecules and different types of substrates at the same time. It is important to understand the DNA morphology on flat surface that serves as a template for DNA based sensors and microarray applications, particularly under an electric field. Taken together, the ability to deposit a single DNA molecule on the electrode is essential to increase its specificity. In our study, we optimize the conditions in order to control a single DNA molecule adsorbing and desorbing to/from the electrode. Simultaneously dynamic imaging enables us to analyze its morphological behavior by real-time Electrochemical Atomic Force Microscopy (EC-AFM) in aqueous conditions. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.008207jes] All rights reserved.