A novel integrated optical sensor for DNA arrays detection

摘要

A novel integrated optical biosensor; that combines optical planar waveguides for illumination with micro lens arrays for collection of fluorescence, is presented in this paper. The sensor is based on laser induced fluorescence detection and will be applied for biochemical or chemical applications such as fluorescence labeled DNA affinity assay. An evanescent field is generated by the optical planar waveguides, which illuminate DNA arrays on the surface of the waveguide. High signal to noise ratio and sensitivity cna be acheived since the evanescent field is tightly confined within the neighborhood of the surface of waveguides and laser noise will scarcely reach the detector. Micro lens arrays with large numerous aperture are combined into the sensor to collect more fluorescent lights form DNA samples induced by the evanescent field. A high sensitive CCD is used for this multi-channel system. The sensor has advantages of ocmpactness, multi-channel detection simultaneously, high sensitivity and good compatibility with biology samples, so it is not only suitable to be used in detection of fluorescent labeled DNA arrays, but also can be used in other life science research like fluorescence immunoassays. The compact design of the sensor allows it to be integrated in a micro total analysis system ( um -TAS) such as a portable DNA diagnostics device.