FPW biosensor with low insertion loss for detection of Tetrahydrocannabinol antigen

Conventional flexural plate-wave (FPW) devices usually have high insertion loss, so we designed focus-type interdigital transducers (IDTs) that can effectively constrain launched wave energy, and adopted a focus-type silicon-grooved reflective grating structure (RGS) to reduce wave propagation loss. The results reveal that the proposed FPW devices have lower insertion loss (−38.698 dB). Then, we used the improved FPW device to develop a novel FPW-based biosensor for rapid detection of Tetrahydrocannabinol (THC) concentration in human urine by integrating. This FPW-THC biosensor has low detection limit (40 ng/mL), high sensitivity (126.67 cm2/g), and high sensing linearity (R-square=0.916).