ENZYME BIOSENSOR BASED ON SURFACE-ACOUSTIC-WAVE DEVICE

In a shear horizontal surface acoustic wave (SH-SAW) propagating throu gh a piezoelectric crystal, shear wave and piezoelectric potential due to piezoelectric effect are combined. SH-SAW can be useful for chemic al sensing in the liquid phase. When the load liquid and propagation s urface are in contact, the change in the electrical property of the li quid can be detected due to the acoustoelectric interaction. This pape r describes a new type of acoustoelectric biosensor with an enzyme mem brane on the SH-SAW propagating plane for detecting pH change in liqui d and reports that the SH-SAW enzyme sensor with urease is highly sens itive in detecting urea. In addition, this paper describes the detecti on limit, aging characteristic, and high sensitivity of the detector.