Ion selective field-effect sensor

Claim 1

In an ion selective field-effect sensor selectively sensitive to a particular cation to be measured, the improvement characterized by using a polymer having a structural unit of a giant heterocyclic compound, which selectively forms a complex with said particular cation, as an ion selective film provided on a surface of a field-effect semiconductor, wherein said polymer is between said giant heterocyclic compound and a member selected from the group consisting of vinyl polymers obtained by radical or ion polymerization of vinyl derivatives of the giant heterocyclic compound; vinyl copolymers obtained by radical or ion polymerization of such a vinyl derivative with a vinyl monomer; a polyamide polymer obtained by polycondensation of a diamino derivative of the giant heterocyclic compound with a dibasic acid halide; a polyester polymer obtained by polycondenstion of a dicarboxylic acid derivative of the giant heterocyclic compound with a glycol; a polyurea polymer obtained by addition polymerization of a diamino derivative of the giant heterocyclic compound with a diisocyanate; a polyurethane polymer obtained by addition polymerization of a diisocyanate derivative of the giant heterocyclic compound with a polyhydric alcohol, a polybasic acid or a polyvalent amine; an epoxy polymer obtained by the addition condensation of an amino derivative of the giant heterocyclic compound with a compound having in its molecule two or more epoxy groups; a polymer obtained by the addition polymerization of the giant heterocyclic compound which comprises an aromatic hydrocarbon group with formaldehyde, chloral or glutaric acid; and a polymer obtained by supporting the giant heterocyclic compound in polymer form by reacting an amino derivative of the giant heterocyclic compound with chloromethylated polystyrene or divinylbenzene crosslinked chloromethylated polystyrene.