enzyme substrate electrode

https://doi.org/10.1351/goldbook.E02160
A sensor in which an ion-selective electrode is covered with a coating containing an enzyme which causes the reaction of an organic or inorganic substance (substrate) to produce a species to which the electrode responds. Alternatively, the sensor could be covered with a layer of substrate which reacts with the enzyme, co-factor or inhibitor to be assayed.
Source:
PAC, 1994, 66, 2527. 'Recommendations for nomenclature of ionselective electrodes (IUPAC Recommendations 1994)' on page 2535 (https://doi.org/10.1351/pac199466122527)