Lithium Tantalate Surface Acoustic Wave Sensors for Bio-Analytical Applications

A novel chip-based measurement system for marker-free detection of affinity and molecular interaction kinetics has been developed. Lithium tantalate (LiTaO
₃
) based Love-wave sensors are utilized as an alternative to quartz as substrate material in order to improve both the sensitivity and the limit-of-detection (LOD). Monitoring the coupling of thrombin to its antibody at low concentrations 1 nM and 10 nM showed phase changes of Deltaphi = 0.10deg and 0.35deg, respectively, for an active sensor area of 5.6 mm
²
. We have found that the estimated detection limit for thrombin is on the order of 0.18 nM for our LiTaO
₃
sensors.