Method for determining analyte concentration in biological fluid using electrochemical sensor

• US 8,383,361 B2
• Filed: 12/14/2011
• Issued: 02/26/2013
• Est. Priority Date: 05/03/2007
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Heller, Adam, Feldman, Benjamin J., Mano, Nicolas, Loo, Yueh-Lin
• Primary Examiner(s): NAFF, DAVID M
• Application Number:
  US13/326,071
• Publication Number:
  US 20120152762A1
• Time in Patent Office: 440 Days
• Field of Search: None
• US Class Current: 435/14
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• 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: C12Q 1/006 for glucose
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• 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

Abstract

A polymer matrix that may coated on an electrode is created by co-crosslinking (1) an adduct of a polyaniline formed by templated oxidative polymerization on a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme. The polymer matrix may be hydrated, and the absorbed water may make it permeable to, for example, glucose. The polyaniline may be polyaniline itself or a substituted polyaniline; the water-soluble crosslinker may be poly(ethylene glycol)diglycidyl ether, and the redox enzyme may be glucose oxidase. The polymer matrix may be produced by co-crosslinking (1) an adduct of an electrically conductive polymer and a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme in a single step at an about neutral pH, curing by drying. After hydration, the crosslinked polymer matrix may form a 3-dimensional glucose-permeable bioelectrocatalyst, catalyzing the electrooxidation of glucose.

Claims

1. A method of determining the concentration of an analyte in a biological fluid, the method comprising:

contacting an electrochemical sensor with the biological fluid, wherein the electrochemical sensor comprises;

a working electrode;

a counter electrode; and

a crosslinked polymer matrix disposed on at least a portion of the working electrode, the crosslinked polymer matrix comprising;

polyaniline or a ring substituted polyaniline and poly(2-acrylamido-2-methyl-propane sulfonic acid) (PAAMSA);

a water soluble crosslinker; and

one or more enzymes, wherein at least one of the enzymes is a redox enzyme; and

determining the concentration of the analyte in the biological fluid.

2. The method according to claim 1, wherein the analyte is glucose.

3. The method according to claim 2, wherein the method further comprises electrooxidizing glucose at a current density of greater than 100 μ

A cm<sup>−

2</sup> at 40 mM glucose concentration at the working electrode.

4. The method according to claim 2, wherein the working electrode is poised at 0.3 V vs. Ag/AgC1 or less.

5. The method according to claim 1, wherein the crosslinked polymer matrix is a hydrogel.

6. The method according to claim 1, wherein the water-soluble crosslinker comprises poly(ethylene glycol)diglycidyl ether.

7. The method according to claim 1, wherein the water-soluble crosslinker is present in an amount of from about 2 weight % to about 30 weight %, based upon the dry weight of the polymer matrix.

8. The method according to claim 1, wherein the redox enzyme is selected from the group consisting of a flavoenzyme, a heme enzyme, and a pyrroloquinoline quinone (POO) enzyme.

9. The method according to claim 1, wherein the redox enzyme is selected from the group consisting of glucose oxidase, glucose dehydrogenase, and peroxidase.

10. The method according to claim 1, wherein the redox enzyme of the crosslinked polymer matrix has an apparent Michaelis-constant obtained from an Edi-Hofstee plot of greater than 10 mM glucose.

11. The method according to claim 1, wherein the crosslinked polymer matrix comprises at least two enzymes, wherein a first enzyme catalyzes a reaction to form a substrate for a second enzyme, and wherein the second enzyme is a redox enzyme.

12. The method according to claim 1, wherein the redox enzyme is present in an amount of from greater than 0 weight % to about 60 weight %, based upon the dry weight of the polymer matrix.