Integrated Love Wave Device Dedicated to Biomolecular Interactions Measurements in Aqueous Media

Mass-sensitive electro-acoustic devices such as surface acoustic wave (SAW)micro-balances, capable to operate with aqueous media are particularly favorable for thedevelopment of biosensors. Their dimensions and physical properties offer a large potentialin biological fluid investigations, especially for measuring physical phenomenon (massdeposition, adsorption, pressure...). In this work, we propose a specific gratingconfiguration to lower the influence of viscosity of fluids which reduces the signal dynamicsof the surface wave transducers. A dedicated liquid cell also has been developed to isolatethe electro-active part of the device. The fabrication of the cell is achieved using theSU-8TMphoto-resist, allowing for manufacturing thick structures preventing any contact between thetested liquids and the transducers. Furthermore, the sensing area has been optimized tooptimize the sensor gravimetric sensitivity. The operation of the sensor is illustrated bydetecting bovine serum albumin (BSA) adsorption in the sensing area.