Dresden 2006 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 40: Poster Session II
AKB 40.24: Poster
Mittwoch, 29. März 2006, 16:30–19:30, P3
Controlling the Surface Density of DNA on Au by Electrically Induced Desorption — •Kenji Arinaga1,2, Ulrich Rant2, Jelena Knežević2, Erika Pringsheim2, Marc Tornow2, Shozo Fujita1, Naoki Yokoyama1, and Gerhard Abstreiter2 — 1Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi 243-0197, Japan — 2Walter Schottky Institut, Technische Universität München, 85748 Garching, Germany
Self-assembled DNA layers on solid surfaces have been of great interest and widely introduced to various techniques for bio-molecular investigations. Recently, we have investigated the active electrical manipulation of oligodeoxynucleotides on Au, employing optical means. We showed that the packing density within the DNA layer crucially determines the free mobility (rotatability) of individual molecules on the surface [1]. While this parameter bears a particular significance, very few investigations have been reported that address methods for controlling the surface density of DNA on Au. In this contribution, we discuss the adsorption mechanisms of thiolated DNA on gold as well as desorption properties under controlled substrate potentials. The adsorption strongly depends on the diffusion of DNA and the ionic strength of electrolyte. On the other hand, we show in situ and in real time that electrochemically induced desorption can efficiently be controlled by tuning the magnitude and application-time of the substrate voltage. As a result, it is demonstrated that this method of electrical desorption provides effective means to adjust the surface density of DNA on gold surfaces.
[1] U. Rant, K. Arinaga et al., Nano Letters 2004, 4, 2441.