Biomedical sensor platform based on optical microresonator array

• Applicant: Professor Dr.-Ing. Andreas Ostendorf
• Subject Area: Microsystems ; Measurement Systems
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 235490255

Within this project, an innovative microsensor platform should be established and tested, which combines in a simple way the high sensitivity of optical microresonators with the selectivity of biochemical processes, like antigene-antibody reactions. The sensor platform consists of a replaceable sensor chip and the readout unit. The sensor chip contains an array of optical microresonators with slightly different sizes. The particles are coated with a selective layer. Illuminated with laser light, some particles show optical resonances which depend strongly on the ratio between the applied wavelength and the diameter of the particle. Some particles are partly in resonance and some are off resonance. The particles radiate therefore with different brightness. This forms a characteristic light intensity pattern. Changes of the surface, e.g. due to adsorption of substances on the surface of the particle, lead to a change of the resonance properties and therefore of the light intensity pattern. The specific coating provides a selective adsorption of the analyte. This makes it possible to detect the analyte. The pattern is recorded by a CCD-camera and processed by a connected PC. The properties of the sensor are investigated exemplarily by means of the pair Streptavidin (as coating) and Biotin (as analyte). With this platform, it should be possible to detect substance quantities e.g. biotin in the range of 1 nM.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Gustav Schweiger