Functional cellular assays with multiparametric silicon sensor chips

Multiparametric silicon sensor chips mounted into biocompatible cell culture units have been used for investigations on cellular microphysiological patterns. Potentiometric, amperometric and impedimetric microsensors are combined on a common cell culture surface on the chip with an area of approximately 29 mm2. Extracellular acidification rates (with pH-sensitive field effect transistors, ISFETs), cellular oxygen consumption rates (with amperometric electrode structures) and cell morphological alterations (with impedimetric electrode structures, IDES) are monitored on single chips simultaneously for up to several days. The corresponding test device accommodates six of such sensor chips in parallel, provides electronic circuitry and maintains the required cell culture conditions (temperature, fluid perfusion system). Sensor data are transformed into quantitative information about microphysiologic conditions. The outcome of this transformation as well as reliability and sensitivity in detection of drug effects is discussed. This is the first report on multiparametric cell based assays with data obtained solely with integrated sensors on silicon chips. Those assays are required in different fields of application such as pharmaceutical drug screening, tumor chemosensitivity tests and environmental monitoring.