Orthogonal Surface Acoustic Wave (SAW) Sensor for Cancer Biomarker Detection with Accelerated Binding Kinetics

A device incorporating both Rayleigh wave and shear horizontal surface acoustic waves is made on a ST-Quartz substrate. The Rayleigh wave induced microfluidic mixing shows effects on accelerating the binding kinetics of real-time sensing between antibody and antigen, which is measured by phase change from the shear horizontal surface acoustic wave direction on the ST-Quartz. Preliminary results on this device show shortened response time and enhanced phase signal when the binding is accelerated by microfluidic streaming from the Rayleigh wave. The device can be fabricated using a low cost, single step photolithography method and can be combined with a small electronic sensor for data readout, which allows for a variety of surface-based biomarker detections on a portable platform. In this work, detection of Carcinoembryonic antigen (CEA) binding with functionalized capture antibody is studied to show the effects of mass loading amplification due to Rayleigh wave microfluidic streaming.