Ion-selective electrodes with poly(vinyl chloride) membranes cast directly on conductive composite substrates are easy to build and have shown their usefulness both in quiescent and flow analysis applications. Matching PVC-composite technology to that of ion-sensitive field-effect transistors (ISFETs) has produced a new type of hybrid chemical sensor. In this novel configuration, a graphite-loaded araldite layer is used to cover the gate opening of encapsulated ISFETs. A poly(vinyl chloride) membrane featuring a plasticiser and an ionophore is cast on top of the conductive composite, rendering the device sensitive to the ion of choice. The resulting hybrid devices show similar electrochemical features when compared to traditional sensors (ISFET + PVC membrane). They also display increased longevity and reduced optical sensitivity when compared with ISFETs featuring transparent PVC membranes. © 1993.
|Journal||Sensors and Actuators: B. Chemical|
|Publication status||Published - 1 Jan 1993|