Dresden 2003 – wissenschaftliches Programm
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MA: Magnetismus
MA 11: Magnetische Messmethoden / Sensoren / Aktoren
MA 11.3: Vortrag
Dienstag, 25. März 2003, 12:45–13:00, HSZ/04
Detection of DNA with magnetic biosensors — •Jörg Schotter1, Hubert Brückl1, Günter Reiss1, Paul-Bertram Kamp2, Anke Becker2, and Alfred Pühler2 — 1Department of Physics, University of Bielefeld, Germany — 2Department of Biology, University of Bielefeld, Germany
Compared to the established fluorescent labeling method, the use of magnetic markers in biochip sensors has important advantages with respect to the detection of biomolecules at low concentrations [1,2]. Additionally, the direct availability of an electronic signal allows the design of inexpensive integrated detection units. The magnetic markers are commercially available superparamagnetic microspheres. We demonstrate the applicability and functionality of Giant Magnetoresistance (GMR) sensors for detecting magnetic markers [3]. The GMR-sensors consist of patterned Cu/NiFe multilayers in the second antiferromagnetic maximum. Hybridization experiments show that our magnetic biosensor can detect complex DNA with a length of about one thousand base pairs down to a concentration of 10 pg/µl. At these low concentrations, the signal to noise ratio of our magnetic biosensor is superior to standard fluorescent detection.
[1] M.M. Miller et al., J. MAGN. MAGN. MATER. 225, 138 (2001) [2] M. Tondra et al., J. VAC. SCI. TECHNOL. A 18(4), 1125 (2000) [3] J. Schotter et al., IEEE T. MAGN. 38 (5), 3365 (2002 )