Urease-immobilized urea electrode and process for preparing the same

• US 4,476,005 A
• Filed: 09/30/1983
• Issued: 10/09/1984
• Est. Priority Date: 10/04/1982
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kobayashi, Teruaki, Tokinaga, Daizo, Karasawa, Yoshiharu, Katori, Akiko
• Primary Examiner(s): Kaplan, G. L.
• Application Number:
  US06/537,511
• Time in Patent Office: 375 Days
• Field of Search: 204/403, 204/1 E, 134/42, 435/12, 435/177, 435/174, 435/817
• US Class Current: 204/403.1
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

Urea electrode comprises a urease-immobilized membrane having added amino groups prepared by dipping an immobilized membrane in an aqueous solution of ethylenediamine or polylysine and an electrode for quantitative determination of ammonium ions. The electrode has a shorter measurement time with a larger electrode output.

Claims

1. A urea electrode comprising a urease-immobilized membrane and an electrode for quantitative determination of ammonium ions, the urease-immobilized membrane having added amino groups in the membrane structure.

2. A urea electrode according to claim 1, wherein the urease-immobilized membrane has at least 10¹⁸ amino groups per 1 cm³ of membrane volume.

3. A urea electrode according to claim 1 or 2, wherein the urease-immobilized membrane is a membrane immobilized by glutaraldehyde.

4. A urea electrode according to claim 1, wherein the urease-immobilized membrane having added amino groups is a membrane prepared by dipping an urease-immobilized membrane in an aqueous solution of a compound having at least two amino groups in one molecule.

5. A urea electrode according to claim 4, wherein the compound is a compound having a molecular weight of not more than 3,000.

6. A urea electrode according to claim 5, wherein the compound is ethylenediamine, guanidine or polylysine.

7. A method for preparing a urease-immobilized membrane having added amino groups in the membrane structure for a urea electrode, which comprises dipping a urease-immobilized membrane in an aqueous solution of a compound having at least two amino groups in one molecule.

8. A method according to claim 7, wherein the compound is a compound having a molecular weight of not more than 3,000.

9. A method according to claim 8, wherein the compound is ethylenediamine or polylysine.