PURPOSE: To permit easy miniaturization and manufacture of multisensors with a simple process and to extend the life of the sensors by forming directly an urease-immobilized film on a pH-ISFET by using a photosensitive resin.
CONSTITUTION: A pH-ISFET element 1 which is an underlying electrode is provided with sources 2 and 4, drains 3 and 5, pseudo-reference electrode 6 and lead wires 7. This pH-ISFET element is the composite type pH-ISFET element constituted of one pH-ISFET(A) consisting of the source 2 and drain 3 and another pH-ISFET(B) consisting of the source 4 and the drain 5 as well as the (pseudo) reference electrode 6. The glucose sensor is manufactured by a method for mounting an urease-immobilized film on the part 8 of the pH-ISFET(A) and not mounting sand film on the another pH-ISFET(B). If there is urea in the sample soln., the urea is decomposed and the pH of the urease-immobilized film generates a difference in the pH of the sample soln. itself monitored by the pH- ISFET(B) having no urease-immobilized film.
HANASATO YOSHIO
NAKAKO MAMIKO
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