Influence of the organic matrix on the properties of membrane coated ion sensor field-effect transistors

Potentiometric sensors with photopolymerized polyacrylate matrix membranes, sensitive to calcium-, potassium- and nitrate- ions, were prepared and studied in batch and flow (FLA) modes. The encapsulated pH-sensitive field-effect transistors with SiO2/Si3N4 gate insulators were used as transducers. Effects of polymer matrix, ionophore and plasticizer of the membrane on the performance, selectivity, dynamic characteristics and durability of ISFETs were studied. The emphasis was made on the investigation of the membrane composition of Ca2+ -ISFET. A new method of the investigation of a dynamic response of the potentiometric sensor ('a method of the maximal response') was introduced. (C) 1999 Elsevier Science S.A. All rights reserved.