Biomedical Engineering Reference
In-Depth Information
Figure 8.7
A. Schematic of surface acoustic wave device with Rayleigh waves. B. Schematic
of surface acoustic wave device with shear horizontal surface waves.
To counteract liquid damping, shear horizontal surface acoustic waves
(SH-SAW) have been used. h is mode of surface wave is less susceptible
to liquid damping because the lateral waves are less damped compared
to the compressional waves. Recently, researchers in Tsukuba, Japan have
reported successful employment of a SH-SAW device for protein immu-
nosensing. h e interaction between thrombin and a thrombin-binding
aptamer (TBA) on a PEG/TBA coimmobilized surface was studied
immobilizing the aptamers between the two input and output IDTs as
shown in Figure 8.8.
h e SH-SAW sensor is very sensitive and its detection limit of throm-
bin by the optimized TBA-T(40)/PEG-b-PAMA(23) surface was around
7.5 pmol. h is sensor complements existing detection mechanisms such as
surface plasmon resonance and the QCM as the SH-SAW sensor detects
both mass as well as viscosity changes on the thin active layer.
