ELECTRON-CONDUCTING CROSSLINKED POLYANILINE-BASED REDOX HYDROGEL, AND METHOD OF MAKING

• US 20090321277A1
• Filed: 05/02/2008
• Published: 12/31/2009
• 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: Loo, Yueh-Lin, Mano, Nicolas, Heller, Adam, Feldman, Benjamin J.
• Granted Patent: US 8,080,385 B2
• Time in Patent Office: Days
• US Class Current: 205/778
• 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 polymer matrix formed by crosslinking:

(1) an adduct of (a) a polymer comprising polyaniline or a ring substituted polyaniline and (b) a polymer acid;

(2) a water-soluble crosslinker; and

(3) one or more enzymes, wherein at least one of the enzymes is a redox enzyme.

2. A polymer matrix according to claim 1, wherein the polymer matrix is hydrated.

3. A polymer matrix according to claim 2 capable of catalyzing the oxidation of a substrate of a redox enzyme at an electrode.

4. A polymer matrix according to claim 3, wherein the substrate is glucose.

5. A polymer matrix according to claim 2 capable of catalyzing the reduction of a substrate of a redox enzyme at an electrode.

6. A polymer matrix according to claim 5, wherein the substrate is hydrogen peroxide.

7. A polymer matrix according to claim 1, wherein the polymer acid comprises sulfonate groups.

8. A polymer matrix according to claim 1, wherein the polyaniline or the ring substituted polyaniline and the polymer acid are present in a molar ratio of from about 1:

0.7 to about 1;

0.99 in the adduct.

9. A polymer matrix according to claim 1, wherein the water-soluble crosslinker comprises poly(ethylene glycol) diglycidyl ether.

10. A polymer matrix 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.

11. A polymer matrix according to claim 1, wherein the redox enzyme is at least one enzyme selected from the group consisting of a flavoenzyme, a heme enzyme, and a PDQ enzyme.

12. A polymer matrix according to claim 1, wherein the redox enzyme is selected from the group consisting of glucose oxidase, glucose dehydrogenase, and peroxidase.

13. A polymer matrix according to claim 1 comprising at least two enzymes, wherein the first enzyme catalyzes a reaction to form the substrate of the second enzyme, and wherein the second enzyme is a redox enzyme.

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

15. An electrode coated with the polymer matrix according to claim 14, wherein the polymer matrix allows the electrooxidation of glucose at a current density of greater than 100 μ

A·

cm<sup>−

2</sup> at 40 mM glucose concentration, at an electrode poised at 0.3 V vs. Ag/AgCl or less.

16. An electrode coated with a polymer matrix according to claim 14, wherein the polymer matrix has an apparent Michaelis-constant obtained from an Edie-Hofstee plot of greater than 10 mM glucose.

17. A polymer matrix according to claim 2, wherein the polymer matrix is permeable to glucose.

18. A method for producing a polymer matrix comprising (1) an adduct of polyaniline or a ring-substituted polyaniline and a polymer acid;

(2) a water-soluble crosslinker; and

(3) a redox enzyme, wherein the electrically conductive polymer, the water-soluble crosslinker, and the redox enzyme are co-crosslinked, the method comprising;

(a) the step of co-crosslinking the polyaniline or a ring-substituted polyaniline and the redox enzyme by the water-soluble crosslinker at about a neutral pH.

19. A method for producing a crosslinked polymer matrix according to claim 18, wherein the adduct of polyaniline or a ring-substituted polyaniline and a polymer acid and a redox enzyme are co-crosslinked by the water-soluble diepoxide after drying on a corrosion resistant conductor surface.

20. A polymer matrix produced by the method according to claim 18.

21. A method of determining glucose, comprising coating the working electrode of a blood glucose test strip with a polymer matrix formed by crosslinking:

(1) an adduct of (a) a polymer comprising polyaniline or a ring substituted polyaniline and (b) a polymer acid;

(2) a water-soluble crosslinker; and

(3) one or more enzymes, wherein at least one of the enzymes is a redox enzyme,

and determining the concentration of glucose in a blood sample with said strip through the use of coulometry.