Improved acoustic-plate-mode biosensor

The design of an improved acoustic-plate-mode (APM) biosensor is presented. The biosensing element consists of a pair of APM delay lines fabricated on an ZX lithium niobate (LiNbO 3) substrate. Each delay line utilizes a single APM and exhibits adjacent-mode rejection superior to previous LiNbO 3 designs, without sacrificing the high sensitivity to electrical effects. The biosensing element is evaluated as an immunosensor using the vector voltmeter (VVM) measurement system. The results show that the improved biosensor is capable of selectively detecting antibody concentrations of 20 ng per ml.