Electrochemical biosensor stability

• US 5,525,511 A
• Filed: 04/28/1993
• Issued: 06/11/1996
• Est. Priority Date: 09/01/1990
• Status: Expired due to Fees

• Current Assignee: Cranfield Biotechnology, Ltd.
• Original Assignee: Environmental & Medical Products, Ltd.
• Inventors: D'Costa, Eric
• Primary Examiner(s): Beisner, William H.
• Application Number:
  US08/050,197
• Time in Patent Office: 1,140 Days
• Field of Search: 435/4, 435/12, 435/14, 435/288, 435/291, 435/817, 204/153.12, 204/153.17, 204/403, 204/415
• US Class Current: 204/403.09
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

An electrochemical biosensor comprising a conductive support member (2) mounted on a substrate (1) and carbon pads (4) overlying the conductors (2) and surmounted by working electrode and reference electrode pads (5) and (6). A membrane (8) applied over the electrodes incorporates a quantity of mediator to facilitate repeated use of the biosensor.

Claims

1. An electrochemical biosensor comprising:

a conductive support member;

an enzyme system including a first mediator immobilized on the support member; and

a covering membrane

incorporating a quantity of a second mediator and covering the enzyme system.

2. A biosensor as claimed in claim 1, wherein the first mediator included in the enzyme system is the same as the second mediator incorporated in the membrane.

3. A biosensor as claimed in claim 1, wherein the second mediator is soluble in a non aqueous solvent.

4. A biosensor as claimed in claim 1 wherein the second mediator is selected from the group consisting of heterofulvalene Pi-donors, metallocenes, quinones, and metal complexes based on platinum group or transition group elements and organic liqands.

5. A biosensor as claimed in claim 1 wherein the membrane comprises a material selected from the group consisting of ethyl hydroxyethyl cellulose, ethyl cellulose, cellulose acetate, polyvinyl chloride, polyurethane, polycarbonate, cellulose nitrate and functionalised aryl polyethers.

6. A biosensor as claimed in claim 1 wherein the second mediator in the membrane is present in a concentration of 5 to 50 mg.g^-1.

7. A biosensor as claimed in claim 6, wherein the concentration is 5 to 20 mg.g^-1.

8. A biosensor comprising:

a conductive support member;

an enzyme system including a first mediator immobilised on the support member; and

a covering membrane incorporating a quantity of a second mediator and covering the enzyme system;

wherein the biosensor provides a substantially quantitative amperometric response when used for 50 repeat tests with an analyte.

9. A biosensor as claimed in claim 8, wherein said first mediator and said second mediator are identical.