Ion selective electrodes

Abstract

An ion-selective electrode (10) including a water-impermeable, non-conductive substrate (12); an electrically conductive layer including a metal/metal salt mixture (14) supported on a surface of the substrate; a hydrophobic, conductive intermediate layer (16) in contact with the metal/metal salt layer and including a salt having suitable ionic mobility such that an electrode potential is rapidly established; a layer (18) including an ion-specific ligand in contact with the intermediate layer; and a water-impermeable barrier layer (20) which overlays the layer including the ion-specific ligand such that a portion of this layer is uncovered, and a method for preparing same, is described. The present ion-selective electrode permits rapid, reproducible measurements of ion concentrations to be made without requiring electrode calibration and in the absence of liquid electrolytes.