Toward biological diagnosis system based on digital versatile disc technology

A novel biosensor utilizing an interference of light reflected at the interfaces of a multilayer structure is proposed. This biosensor detects analytes by monitoring the changes in reflection intensity due to their adsorption to the sensor surface, on which functional biomolecules are immobilized to specifically bind to the analytes. The proposed biosensing instrument is based on a commercial digital versatile disc (DVD) system, which allows the instrument to be small and inexpensive. For the preliminary examination, SiO2 thin films with a well-defined thickness were deposited on the sensor surface. The reflection intensity varied almost linearly depending on the thickness of the SiO2 films in a thickness range of 2-10nm. Subsequently, it was demonstrated that biotin-streptavidin binding events were clearly detectable on a rotating disc substrate at a constant linear velocity of 4.0m/s. We named this interference-based biosensor BioDVD, which is expected to be useful for high throughput multi-analyte bioassays.