Polymeric membranes for silicon based (bio)sensors

During the last decade, chemical and biochemical sensor research has benefited from the availability of new technologies and materials. New embodiments of classical devices have resulted from the use of e.g., solid state technology for the realization of the transducers. In this paper we describe several examples of membrane deposition techniques used in connection with planar, silicon based electrochemical transducers. Casting and electrochemical deposition of glucose oxidase containing membranes are described for the fabrication of glucose enzyme electrodes. Photolithographic patterning of polyacrylamide hydrogel and of siloxane based gas permeable membrane is used for the realization of an amperometric oxygen sensor and an ISFET-based pCO2 device. The last example is that of a free-chlorine sensor for which the photolithographic patterning of the polyHEMA hydrogel layer is described.