Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 8: Neue Methoden
CPP 8.3: Vortrag
Mittwoch, 26. März 2003, 17:30–17:45, ZEU/160
Development of a Biosensor Device Based on Silicon on Insulator (SOI) — •Michael G. Nikolaides1, Stefan Rauschenbach1, Marc Tornow2, and Andreas R. Bausch1 — 1Lehrstuhl für Biophysik E22, Technische Universität München, 85747 Garching, Germany — 2Walter Schottky Institut, Technische Universität München, 85748 Garching, Germany
There is growing need for new detection schemes of biomolecular interactions as the common fluorescent labeling techniques are limiting the applicability of DNA or Protein arrays. Increasingly sophisticated techniques are being developed to provide versatile techniques for the label free detection of molecular interactions.
We present a novel surface sensitive technique based on commercially available silicon on insulator (SOI) substrates. A very thin conductive silicon layer, covered only by the native oxide, is isolated from the bulk wafer through an additional buried oxide. By very sensitive electrical transport measurements in this layer, we are able to detect changes occurring at the surface of the device. Changes in surface potential as well as changes of the surface states will influence the space charge region in the sensing layer and therefore influence its conductivity. Thus intermolecular interactions can be detected in real time with a very high sensitivity. We present the detection of different salt concentrations in electrolytes and the unspecific adsorption of small numbers of charged biomolecules. The results are in good agreement with theoretical predictions.