Biosensor using shear-horizontal surface acoustic wave

This paper describes an immunoassay-based biosensor which is composed of a disposable sensor device and a prototype electric reader with 14 × 10 × 4 cm
³
in size. The sensor devices are fabricated using a 250 MHz shear horizontal surface acoustic wave (SH-SAW) delay-line on quartz substrates, which is composed of a transmitting interdigital transducer (IDT), receiving IDT, and a biochemical reaction area between them. The biochemical reaction area is covered with antibodies. The electric reader is connected to the sensor device and detects antigen-antibody reactions. The reader has a burst circuit to eliminate unwanted electro-magnetic feed through signals. A model immunoassay based upon human serum albumin detection is presented. A model assay system for the sensitive measurement of human C reactive protein (C-RP) is also shown.