Analysis of Mass Loading Effect on Guided Shear Horizontal Surface Acoustic Wave on Liquid/Au/Quartz Structure for Biosensor Application

A numerical analysis of a shear horizontal surface acoustic wave (SH-SAW) immunoassay biosensor has been investigated. The numerical calculation method proposed by Campbell and Jones has generally been used to calculate SAW propagation characteristics. In this paper, a numerical calculation method for SH-SAW propagation characteristics, which is a modified method of Campbell and Jones involving the effect of liquid viscosity is applied to quartz. A mass loading sensitivity of a 250 MHz SH-SAW delay-line biosensor was calculated and compared with the experimental results. It can be concluded from the results that viscosity sensitivity is dominant over mass loading sensitivity for 250 MHz SH-SAW biosensors.