title: Comparison of a prototype magnetoresistive biosensor to standard fluorescent DNA detection.
abstract: We present a comparative analysis of a magnetoresistive biosensor to standard fluorescent DNA detection. The biosensor consists of giant magnetoresistive (GMR) type Cu/Ni(80)Fe(20) multilayers in the second antiferromagnetic coupling maximum. Each of the 206 elements of the magnetoresistive biosensor is patterned into a spiral-shaped line that can cover the area of a typical DNA spot (70 microm diameter). The probe DNA is assembled on top of the sensor elements in different concentrations ranging from 16 pg/microl to 10 ng/microl. Complementary biotin-labeled analyte DNA is hybridized to the probe DNA at a concentration of 10 ng/microl. A number of different commercially available magnetic microspheres are investigated to determine the most appropriate markers. The experimental comparison shows that the relative sensitivity of the magnetoresistive biosensor is superior to the fluorescent detection at low probe DNA concentrations.
authors.affiliation: Department of Physics, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany. schotter@physik.uni-bielefeld.de
authors.forename: J
authors.initials: J
authors.lastname: Schotter
authors.forename: P B
authors.initials: PB
authors.lastname: Kamp
authors.forename: A
authors.initials: A
authors.lastname: Becker
authors.forename: A
authors.initials: A
authors.lastname: Pühler
authors.forename: G
authors.initials: G
authors.lastname: Reiss
authors.forename: H
authors.initials: H
authors.lastname: Brückl
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000032:analysis*; D003627:Data Interpretation, Statistical; D008280:Magnetics / Q000295:instrumentation*; D008854:Microscopy, Electron
chemical_list: D004247:DNA