Electrical Detection of Biomolecular Interactions by Thin Film Resistors

Biosciences rely increasingly on the simultaneous and quantitative detection of a large number of biomolecular interactions. For the emerging field of system biology miniaturized, parallel and quantitative detection methods of protein interactions or DNA hybridizations is critical. Further more, for biomedical and pharmaceutical research, detecting the interaction of small molecules or peptides with membranes or membrane proteins is becoming increasingly important. Most state of the art detection methods currently employed are based on the labeling of the analytes with fluorophores, chemiluminescent, or redox markers in order to detect their specific interactions with immobilized receptor molecules. However, these methods can be problematic because labeling is an additional step in sample preparation and can alter the overall structure of the analyte in a way that may affect its binding behavior.
The direct electrical detection of molecular interactions with biofunctionalized semiconductor devices would circumvent these obstacles since no labeling is needed; miniaturization could even allow the detection on single cell levels.
In our group, we develop biosensing semiconductor devices based on SOI (Silicon on Insulator). The nanometer thin film resistors are biofunctionalized with receptor molecules. One currently pursued strategy is to use a biomimetic lipid membranes which allow the study of protein - membrane interactions. The ultimate goal is to achieve a highly parallel specific and sensitive detection of small biomolecules. The research is relying on the integration of approaches from Biophysics, Biochemistry and Semiconductor Sciences.

Relevant Publications:

  1. S. Rammensee, U. Slotta, T. Scheibel, A.R. Bausch (2008). Assembly mechanism of recombinant spider silk proteins. Proceedings of the national academy of sciences U.S.A., in print.
  2. Y. Luan, O. Lieleg, B. Wagner and A.R. Bausch (2008). Micro- and Macromechanical Properties of Isotropically Cross-linked Actin Networks. Biophysical Journal, 94: 688-693.
  3. O. Lieleg, M. López-García, C. Semmrich, J. Auernheimer, H. Kessler and A.R. Bausch (2007). Specific Integrin Labeling in Living Cells Using Functionalized Nanocrystals. SMALL, 3, 1560-1565.