Surface Acoustic Wave (SAW) Biosensor Chip System - a Promising Alternative for Biomedical Applications

Surface acoustic wave (SAW) biosensors based on horizontally polarized surface shear waves enable label-free, sensitive and cost-effective detection of biomolecules in real time. Binding reactions on the sensor surface are detected by determining changes in surface wave velocity caused mainly by mass loading in the sensing layer. Typically SAW devices are coated with biochemically sensitive layers including analyte-specific capture molecules or ligands. For the development of an array, single SAW devices first are embedded in polymer housings, however, the sensitive sensor area still remains accessible for surface modification. Advantages of those SAW biosensor chips are simple handling and low consumption of chemicals used in the coating process. An integrated microfluidic chip connects eight SAW biosensor chips to an array. An additional feature of the microfluidic chip is the direct connection between sample and biosensor chips allowing small sample volumes. This SAW biosensor chip array enables simultaneous analysis of multiple analytes in one sample. A potential application of such an array is the use in future point-of-care (POC) devices. First affinity experiments using this set-up will be shown.