Multi-parameter detection of (bio-)chemical and physical quantities using an identical transducer principle

A multi-functional hybrid sensor module and multi-parameter measuring system for the detection of six (bio-)chemical and physical parameters (pH, penicillin concentration, diffusion coefficients of ions, temperature, flow velocity and flow direction) is realised using the same transducer principle. Here, an ion-sensitive field-effect transistor (ISFET), which is well known as a (bio-)chemical sensor, is also utilised as a physical sensor. Thus, more parameters can be determined than the number of sensors present in the modular system (so-called “high order” system). The multi-parameter detection is achieved by means of sequentially or simultaneously scheduling of different sensor arrangements and/or different operation modes. The results of testing of the developed hybrid module in different sensor configurations and basic characteristics of individual sensors, including an ISFET-based “time-of-flight”-type flow-velocity and flow-direction sensor employing the in situ electrochemical generation of chemical tracers, like H+- or OH−-ions, are presented and discussed. A novel diffusion-coefficient sensor that is based also on an ISFET is introduced and experimentally demonstrated.