Immobilized enzyme membrane
First Claim
1. An enzyme electrode apparatus for electrochemically analyzing a substance in a sample solution, which comprises a vessel for encasing an electrolyte solution therein;
- an anode;
a cathode;
an immobilized enzyme membrane containing a skin layer that functions as a barrier provided at a working face of the anode and/or cathode; and
an electrolyte solution in the vessel;
the immobilized enzyme membrane being provided by an asymmetrical membrane having a thickness of 30-300 μ
m integrally formed from a skin layer substantially incapable of permeating an enzyme therethrough, but capable of permeating a gas and a liquid therethrough, and a sponge layer having sufficient porosity for retaining a necessary amount of the enzyme and pores intercommunicated with one another throughout the sponge layer, the enzyme being immobilized in the pores of the sponge layer by cross-linking, the skin layer having a thickness of 0.1-3 m m and the sponge layer having a porosity of 50-90%;
the skin layer and the sponge layer being formed from the same material.
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Accused Products
Abstract
An immobilized enzyme membrane for use at the working face of an electrochemical electrode is prepared which comprises an asymmetrical membrane integrally formed from a skin layer substantially incapable of permeating an enzyme therethrough but capable of permeating a gas and a liquid, and a sponge layer having pores containing an enzyme immobilized therein by crosslinking and which pores intercommunicate with one another throughout the sponge layer and provide sufficient porosity for retaining a necessary amount of the enzyme. The immobilized enzyme membrane contains a large amount of enzyme, has good diffusion and permeability, and has stabilized enzyme activity for a prolonged period of time. Additionally, there is obtained a quick response time and good analytical precision when the immobilized enzyme membrane is used at the working face of an electrode of electrochemical measuring instruments.
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Citations
7 Claims
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1. An enzyme electrode apparatus for electrochemically analyzing a substance in a sample solution, which comprises a vessel for encasing an electrolyte solution therein;
- an anode;
a cathode;
an immobilized enzyme membrane containing a skin layer that functions as a barrier provided at a working face of the anode and/or cathode; and
an electrolyte solution in the vessel;
the immobilized enzyme membrane being provided by an asymmetrical membrane having a thickness of 30-300 μ
m integrally formed from a skin layer substantially incapable of permeating an enzyme therethrough, but capable of permeating a gas and a liquid therethrough, and a sponge layer having sufficient porosity for retaining a necessary amount of the enzyme and pores intercommunicated with one another throughout the sponge layer, the enzyme being immobilized in the pores of the sponge layer by cross-linking, the skin layer having a thickness of 0.1-3 m m and the sponge layer having a porosity of 50-90%;
the skin layer and the sponge layer being formed from the same material. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- an anode;
Specification