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Electro-Magnetic Microbead Technology for Biosensor Application

Objective

A new base technology for extremely sensitive electromagnetic integrated sensors for the on-chip detection of analytes such as antibodies or DNA as well as for a simple multiple determination of binding forces is developed. Microbead labelled analytes are specifically captured by e.g. antibody-antigen interaction at microelectrodes. The detection of analytes is based on the strong impact of the labels on a space-dependent electrochemical current generated by microelectrodes. This current is switched from high level to low level when the microbeads are captured and is switched back when the microbeads are removed by magnetic forces. The proposed technology will have the potential to stimulate the development of a new generation of smart analytical sensor devices with extremely low detection limits and allow an alternative way to monitor relevant substances without consumption of critical additional solutions and reagents.

OBJECTIVES
The objectives of the experimental assessment project are:1) Reduce the technical risk associated with the uncertainty about the proposed measuring principle with regard to the qualitative and quantitative detection of a biochemical reaction.2) Reduce to an acceptable level the technical risk associated with the uncertainty about the IC compatible technological processes pertinent with the manufacturing of the novel sensors.

DESCRIPTION OF WORK
UOB (U.K.) is responsible for the development and manufacture of the transducers. These transducers with dimensions of only few square millimetres will bear an array of 100 platinum microelectrodes most of which can be separately addressed. Each single electrode will be surrounded by a micro-coil for the generation of controlled magnetic forces acting on the particles. Especially the electrode array material, the electrode diameter and the inter-electrode spacing are relevant properties for the transducer design and layout concept. After the concept phase the transducers will be fabricated in the semiconductor facilities of the transducer partner. ICB (Germany) is responsible for the characterisation of the transducers fabricated by the partner and the subsequent development of a sensor prototype. After the transducer characterisation the immobilisation procedure will start with a spatial deposition of dextran layers for coupling the analyte specific capture antibodies.

A system will be developed for the generation of magnetic forces. After preliminary tests with unbound magnetic microbeads measurements will start with biochemically modified microbeads and activated microelectrodes. The measuring procedure will be performed with an electrochemically active redox system. The electrical current of each array electrode is monitored while the immuno reaction between analyte molecules (antigens) and antibody modified microbeads proceeds. Subsequently, a steady increasing magnetic force is applied to the magnetic beads until the microbeads are removed from the electrodes. The ratio of high-level signals to low-level signals will be measured and the analyte concentration will be determined. Different analyte concentration will be injected into the fluid system to obtain a proof of principle of the new detection system.

Funding Scheme

ACM - Preparatory, accompanying and support measures

Coordinator

INSTITUT FUER CHEMO- UND BIOSENSORIK GMBH
Address
Mendelstrasse 7
48149 Muenster
Germany

Participants (1)

THE UNIVERSITY OF BIRMINGHAM
United Kingdom
Address
Edgbaston
B15 2TT Birmingham