A capacitive biosensor based on ultrathin Si membranes

A biosensor which takes advantage of surface stress changes during biological interactions and is able to translate them into a capacitive signal is presented. The sensor consists of an ultrathin silicon membrane on which receptor molecules are immobilized. During biomolecular interactions, the surface stress changes and the membrane deflects resulting in a change in device capacitance. The biosensor is part of a 16 times 16 array thus allowing for the making of larger assays with the concurrent sensing of multiple biological targets. First results using the biotin-steptavidin system are presented.