Love Wave SAW Biosensors for Detection of Antigen-antibody Binding and Comparison with SPR Biosensor

摘要

In this study, 77 and 155 MHz Love wave surface acoustic wave (SAW) biosensors were fabricated to detect antigen-antibody reactions in liquid environments. The single-interdigital transducer (IDT) on the quartz crystal substrate was found to be not suitable for Love wave SAW biosensor because of its signal distortion due to triple transit echo (TTE) between the IDT fingers. As a waveguide layer for the Love wave SAW biosensor, SU-8 photoresist was coated on a quartz crystal substrate with double-IDT patterns. Anti-mouse IgG was immobilized on the sensing area with a protein G layer bound to a gold surface. The minimum detectable concentrations of mouse IgG for 77 and 155 MHz Love wave SAW biosensors and a surface plasmon resonance (SPR) biosensor were found to be 2.5, 1, and 1 ug/mL, respectively. The fabricated Love wave SAW and SPR biosensors showed similar performances in detectable concentrations of mouse IgG and in coefficient of determination.