Diagnostic electrode membranes utilizing specific enzyme/Ionophore pairs

Claim 2

An electrode membrane for the determination of an analyte in a liquid test sample, comprising a hydrophobic, chemically inert, dielectric polymer having bound to a surface thereof an enzyme capable of reacting with the analyte to produce an ion, and having dispersed therein an ionophore capable of complexing with the ion.

Claim 3

The membrane of Claim 1 wherein the polymer is selected from the group consisting of poly(vinyl chloride), cellulose acetate, poly(bisphenol-A carbonate), polysiloxane/poly(bisphenol-A carbonate) block copolymer, poly(methylmethacrylate), poly(vinylidene chloride), polystyrene, lower alkyl acrylate and methacrylate polymers and copolymers and polyurethane.

Claim 4

The membrane of Claim 2 wherein the polymer is poly(vinyl chloride).

Claim 5

The membrane of Claim 2 wherein the poly-(vinyl chloride) is carboxylated.

Claim 6

The membrane of Claim 1 wherein the enzyme is urease and the ionophore is nonactin.

Claim 7

The membrane of Claim 1 further comprising a plasticizer.

Claim 8

The membrane of Claim 5 wherein the plasticizer is dioctyl adipate.

Claim 9

The membrane of Claim 5 wherein the urease is bound to the membrane surface using a coupling agent.

Claim 10

The membrane of Claim 8 wherein the coupling agent is glutaraldehyde.

Claim 11

An electrode half-cell comprising (a) a dimensionally stable, chemically inert, electrically insulating substrate layer having coated thereon (b) a terminated layer of electroconductive material, the conductivity of which is at least 1 x 1 0 2 (ohms-cm) -1 having coated thereon (c) a layer of finely divided particles of carbon uniformly dispersed in a matrix of organic polymeric binder having coated thereon (d) a hydrophobic, chemically inert, dielectric polymer membrane having an ionophore dispersed therein, the membrane having an impedance at least two orders of magnitude greater than the impedance of the carbon layer, the interface between the carbon dispersion layer and the membrane comprising a zone in which the layers are partially interdiffused, the membrane having bound on its external surface, (e) an enzyme capable of reacting with a non- ionic analyte to produce an ion capable of complexing with the ionophore.

Claim 12

An electrode half-cell comprising (a) a dimensionally stable, chemically inert, electrically insulating substrate layer having coated thereon (b) a terminated layer of electroconductive material, the conductivity of which is at least 1 x 1 0 2 (ohms-cm) -1 having coated thereon (c) a layer of finely divided particles of carbon uniformly dispersed in a matrix of organic polymeric binder having coated thereon (d) a hydrophobic, chemically inert, dielectric polymer membrane having an ionophore dispersed therein, the membrane having an impedance at least two orders of magnitude greater than the impedance of the carbon layer, the interface between the carbon dispersion layer and the membrane comprising a zone in which the layers are partially interdiffused, the membrane having bound on its external surface, (e) an enzyme capable of reacting with a non- ionic analyte to produce an ion capable of complexing with the ionophore.

Claim 13

An electrode whole cell for the differential potentiometric measurement of a nonionic analyte in a test sample, comprising: a sensing half cell and a reference half cell, the sensing half cell being the half cell defined in Claim 10 and the reference half cell comprising

Claim 14

(a) a dimensionally stable, chemically inert. electrically insulating substrate layer having coated thereon (b) a terminated layer of electroconductive material, the conductivity of which is at least 1 x 10 2 (ohms-cm) -1 having coated thereon (c) a layer of finely divided particles of carbon uniformly dispersed in a matrix of organic polymeric binder having coated thereon (d) a hydrophobic, chemically inert, dielectric polymer membrane having the ionophore dispersed therein, the membrane having bound to its external surface, (e) a nonenzymatic protein.

Claim 15

(a) a dimensionally stable, chemically inert. electrically insulating substrate layer having coated thereon (b) a terminated layer of electroconductive material, the conductivity of which is at least 1 x 10 2 (ohms-cm) -1 having coated thereon (c) a layer of finely divided particles of carbon uniformly dispersed in a matrix of organic polymeric binder having coated thereon (d) a hydrophobic, chemically inert, dielectric polymer membrane having the ionophore dispersed therein, the membrane having bound to its external surface, (e) a nonenzymatic protein.

Claim 16

The whole cell of Claim 11 wherein the nonenzymatic protein is albumin.

Claim 17

The whole cell of Claim 11 wherein the sensing half cell and the reference half cell are disposed on the same substrate layer in spaced apart relationship.