Detecting method of chemical substance by chemically sensitive element of insulated-gate transistor structure

Abstract

Abstract PURPOSE: To easily detect many kinds and small quantities of chemical substances, by performing the detection on the basis of a bias voltage which is selectively applied to a reference electrode so that a prescribed current flows through the source and drain of each element. CONSTITUTION: A particular substance is detected on the basis of a bias voltage which is applied to a reference electrode under selective control so that a prescibed current flows through the soruce and drain of each chemically sensitive element. The ion-sensitive sections 23W25 of an ion sensor 22, which has insulated-gate transistor structure on an identical semiconductor substrate and is selectively sensitive to three desired kinds of ions, are placed in contact with a liquid 21 to be examined. The bias voltage applied to the reference electrode 26 is controlled by a potential regulation circuit 30 so that the potential on a point A of a reference resistor 29 takes a prescribed level. The concentration and activity of particular ions in the liquid 21 are determined from the bias voltage level measured across output terminals 38, 39. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Kiyozo Koshiishi

Bibliographic Details