Novel Love mode surface acoustic wave based immunosensors

Love mode surface acoustic wave (SAW) immunosensors were developed. The Love mode guiding layers in these sensors are ZnO and SiO2 thin films. It is shown that mass sensitivity of the devices with ZnO layer are larger than that of with SiO2 guiding layers. A system comprising dual delay line, based on ZnO/90° rotated ST-cut quartz crystal devices, was set up for conducting the immunosensing experiments. In these experiments adsorption of rat immunoglobulin G onto the active area of the sensor was monitored. Upon exposure to solutions containing IgG, the operational frequency of the system changed due to the interaction of IgG and a gold surface on the active area of the sensor. Mass sensitivities were measured and frequency responses to various IgG concentrations are presented.