Electrochemical cncentration detector method

• US 4,909,908 A
• Filed: 10/27/1988
• Issued: 03/20/1990
• Est. Priority Date: 04/24/1986
• Status: Expired due to Fees

• Current Assignee: Jensen, Joel F., Madou, Marc J., Pepi Ross, Sharon W. Wing, Virginia G. Rimer, Zoila Reyes
• Original Assignee: Jensen, Joel F., Madou, Marc J., Pepi Ross, Sharon W. Wing, Virginia G. Rimer, Zoila Reyes
• Inventors: Jensen, Joel F., Madou, Marc J., Ross, Pepi, Rimer, Virginia G., Wing, Sharon W., Reyes, Zoila
• Primary Examiner(s): Tung, T.
• Application Number:
  US07/263,564
• Time in Patent Office: 509 Days
• Field of Search: 204/1 T, 204/1 E, 204/1 P, 204/403, 204/415, 435/180, 435/817
• US Class Current: 205/778
• 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: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

Electrochemical biosensor systems or apparatus, components thereof, and methods for quantitatively measuring or assaying concentrations of selective substrates or metabolites in aqueous media as a function of electrochemical response to hydrogen peroxide concentration, using immobilized enzyme electrode means selective for the substrate or metabolite being measured.

Claims

1. An amperometric assay method for measuring the concentration of a hydrogen peroxide-yielding substrate in an aqueous sample as a function of amperometric response to enzymatically generated hydrogen peroxide, to provide a direct measurement of the concentration of said substrate, which comprises:

diffusing a sample containing said substrate through a biocompatible, outer permeable membrane of polyurethane/butadiene resin which selectively restricts the passage of undesired substances which interfere with quantitative H₂ O₂ detection and through an inner permeable membrane of a polyvinyl acetate and polyethylene glycol modified poly(styrene maleic anhydride) polymer having at least one immobilized enzyme therein, an enzyme having amino groups covalently bonded to the anhydride polymer groups in said polymer, said inner membrane being in interfacial contact with said outer membrane, said enzyme being selective to the substrate to be assayed and, to catalytically convert said substrate by means of an oxidation/reduction mechanism, and thereupon release H₂ O₂ detectable at a planar electrode which is disposed under said inner membrane, which detector electrode senses H₂ O₂ concentration as a measure of the concentration of the substrate being assayed.

2. The process of claim 1, wherein said aqueous sample is a body fluid.

3. An amperometric assay method for measuring the concentration of glucose in an aqueous sample as a function of the amperometric response to enzymatically generated hydrogen peroxide, to provide a direct measurement of the concentration of the glucose, which comprises:

(a) diffusing a sample containing glucose through a biocompatible, outer permeable membrane of polyurethane/butadiene resin which selectively restricts the passage of undesired substances which interfere with quantitative H₂ O₂ detection and through an inner permeable membrane having glucose oxidase immobilized therein to catalytically release H₂ O₂ from glucose in said substrate, said inner membrane being in interfacial contact with said outer membrane; and

(b) measuring the released H₂ O₂ at a planar electrode which is disposed under said inner membrane.

4. The process of claim 3, wherein said aqueous sample is a body fluid.