Multi ion-sensor arrays: Towards an 'electronic tongue'

Abstract

In this work ion-selective arrays based on spray-coated electrolyte-gated carbon-nanotube field-effect transistors will be used in an example application for water quality assessment. Several cations like Na+, K+, Ca2+ and anions like Cl- and NO3- are detected with the ion-selective sensor arrays in different bottled mineral waters. For the ion-selective arrays the sensing results of two different array configurations will be compared: an array with six transistor structures and one common gate electrode or six different planar gate electrodes with one common read-out CNT-FET. These ion-selective sensor array will have various applications in the fields of biomedical diagnostics, soil-quality testing and water-control measurements.