AVS 53rd International Symposium
    Nucleic Acids at Surfaces Topical Conference Monday Sessions
       Session DN-MoA

Paper DN-MoA8
Electrical Manipulation of DNA on Metal Substrates: Electric Interactions, Molecular Dynamics, and Implications of Hydrodynamic Flow

Monday, November 13, 2006, 4:20 pm, Room 2014

Session: Nucleic Acids at Surfaces II
Presenter: U. Rant, Walter Schottky Institute, Tech. Univ. Munich, Germany
Authors: U. Rant, Walter Schottky Institute, Tech. Univ. Munich, Germany
K. Arinaga, Walter Schottky Institute, Germany & Fujitsu Labs Ltd., Japan
C. Hautmann, Walter Schottky Institute, Tech. Univ. Munich, Germany
S. Scherer, Walter Schottky Institute, Tech. Univ. Munich, Germany
E. Pringsheim, Walter Schottky Institute, Tech. Univ. Munich, Germany
S. Fujita, Fujitsu Labs Ltd., Japan
N. Yokoyama, Fujitsu Labs Ltd., Japan
M. Tornow, Walter Schottky Institute, Tech. Univ. Munich, Germany
G. Abstreiter, Walter Schottky Institute, Tech. Univ. Munich, Germany
Correspondent: Click to Email
We present experimental investigations addressing the response of surface-tethered oligonucleotides to electric fields at the metal/solution interface. By applying AC potentials to the supporting gold substrates, the DNA layer conformation can be efficiently modulated using driving frequencies ranging up to the kHz regime. Simultaneously, optical energy-transfer methods are employed to monitor the layer structure in-situ and in real-time. We discuss electric interactions between the charged substrate and the DNA and elucidate how the manipulation efficiency is determined by the electrode bias and electrolyte screening effects. Time-resolved measurements reveal intriguing molecular dynamics of nucleic acids in surface-confined fields and are compared to hydrodynamic simulations. In addition, we show the implications of lateral hydrodynamic flow on the DNA layer structure. The presented results are expected to be generally representative for charged polymers exposed to short-ranged electric fields at surfaces, and, moreover, are of significant importance for the design of a novel type of actively controlled biosensors based on switchable DNA layers.