title: A novel Urushi matrix chloride ion-selective field effect transistor.
abstract: A durable chloride ion-selective field effect transistor (ISFET) is proposed with Urushi as the membrane matrix. The chloride ion-sensing material is a quaternary ammonium chloride: trioctylmethylammonium chloride (TOMA-Cl) or tridodecylmethylammonium chloride (TDMA-Cl). The optimum composition of the Urushi membrane was found by use of Urushi ion-selective electrodes. The mixture with the most favourable composition was coated on the gate region of the FET device. The Urushi ISFET with TDMA-Cl proved to be superior to that with TOMA-Cl, in sensitivity, linearity and selectivity. The Urushi ISFET with TDMA-Cl showed a linear response of about -51 mV per decade change of chloride ion activity in the range 10(-4)-1M. The Urushi ISFET showed excellent stability and durability for over two months, because of strong adhesion of the membrane to the Si(3)N(4) gate.
authors.affiliation: Government Industrial Research Institute, Osaka, Midorigaoka 1-8-31, Ikeda City, Osaka Pref., 563, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Wakida
authors.forename: M
authors.initials: M
authors.lastname: Yamane
authors.forename: K
authors.initials: K
authors.lastname: Hiiro