SENSOR WITH IMPROVED SHELF LIFE

• US 20080121533A1
• Filed: 10/29/2007
• Published: 05/29/2008
• Est. Priority Date: 03/16/1999
• Status: Abandoned Application

• Current Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Hodges, Alastair, Chatelier, Ronald
• Application Number:
  US11/926,369
• Publication Number:
  US 20080121533A1
• Time in Patent Office: Days
• US Class Current: 205/775
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61N 1/0476 Array electrodes (including any electrode arrangement with more than one electrode for at least one of the polarities)
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: G01N 27/30 Electrodes, e.g. test electrodes; Half-cells G01N27/414 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

Abstract

The present invention provides a metal electrode stabilised by a coating, the coating comprising a sulfur containing moiety in its molecular structure. The coating may also include a hydrophilic group and a spacer between the sulfur containing moiety and the hydrophilic group. Preferably, the sulfur containing moiety is selected from the group comprising thiol, disulfide and SOx, and the hydrophilic group is selected from the group comprising hydroxyl, amine, carboxyl, carbonyl, oligo (ethylene oxide) chain, and zwitterionic species. Compounds useful in the present invention include 2-mercaptoethanol, 2-mercaptoethylamine, 3-mercaptopropionic acid, thiophene, 4-carboxythiophene, cysteine, homocysteine, and cystine.

Claims

1. A coated metal electrode, comprising:

a metal electrode; and

a coating layer disposed on at least one side of the metal electrode, the coating layer comprising a compound, the compound consisting of a sulphur-containing moiety, a hydrophilic group, and a spacer between the sulphur-containing moiety and the hydrophilic group,

wherein a temporal stability of the coated metal electrode is greater than a temporal stability of a corresponding uncoated metal electrode.

2. The coated metal electrode of claim 1, wherein a fill speed of the coated metal electrode is less than a fill speed of a corresponding uncoated metal electrode.

3. The coated metal electrode of claim 1, further comprising a surfactant layer over the coating layer.

4. The coated metal electrode of claim 1, wherein the coating is selected from the group consisting of 2-mercaptoethanol, 2-mercaptoethylamine, 3-mercaptopropionic acid, thiophene, 3-carboxythiophene, L-cysteine, L-cystine, D-cysteine, D-cystine, L-homocysteine, and L-homocystine.

5. The coated metal electrode of claim 1, wherein the coating is a stereospecific compound.

6. The coated metal electrode of claim 5, wherein the stereospecific compound comprises a mixture of D isomers and L isomers of said compound.

7. The coated metal electrode of claim 5, wherein the stereospecific compound comprises a D isomer.

8. The coated metal electrode of claim 5, wherein the stereospecific compound comprises an L isomer.

9. A method of preparing a metal electrode stabilized by a coating, the method comprising:

providing a metal electrode;

contacting the metal electrode with a substance comprising a compound, the compound consisting of a sulfur-containing moiety and a hydrophilic group, whereby a coated metal electrode is obtained, the coated metal electrode having a temporal stability greater than a temporal stability of a corresponding uncoated metal electrode; and

applying a surfactant layer to the coated metal electrode.

10. The method of claim 9, wherein the surfactant and substance are applied simultaneously.

11. The method of claim 9, wherein the surfactant is applied to the electrode subsequent to the application of the substance.

12. The method of claim 9, wherein a fill speed of the coated metal electrode is less than a fill speed of a corresponding uncoated metal electrode.

13. A method of preparing a metal electrode stabilized by a coating, the method comprising:

providing a metal electrode; and

contacting the metal electrode with a substance comprising a compound, the compound consisting of a sulfur-containing moiety, a hydrophilic group, and a spacer between the sulphur-containing moiety and the hydrophilic group, whereby a coated metal electrode is obtained, the coated metal electrode having a temporal stability greater than a temporal stability of a corresponding uncoated metal electrode.

14. The method of claim 13, further comprising the step of overcoating the substance with a surfactant.

15. The method of claim 14, wherein the surfactant and substance are applied simultaneously.

16. The method of claim 14, wherein the surfactant is applied to the electrode subsequent to the application of the substance.

17. The method of claim 13, wherein a fill speed of the coated metal electrode is less than a fill speed of a corresponding uncoated metal electrode.

18. A method of sensing an analyte, the method comprising:

contacting a sample comprising an analyte to a metal electrode, the metal electrode comprising a coating, the coating comprising a compound, the compound consisting of a sulphur-containing moiety, a hydrophilic group, and a spacer between the sulphur-containing moiety and the hydrophilic group, wherein a temporal stability of the coated metal electrode is greater than a temporal stability of a corresponding uncoated metal electrode; and

obtaining a measurement indicative of a presence of the analyte in the sample.

19. The method of claim 18, wherein the coating further comprises a surfactant layer.

20. The method of claim 18, wherein the coating is selected from the group consisting of 2-mercaptoethanol, 2-mercaptoethylamine, 3-mercaptopropionic acid, thiophene, 3-carboxythiophene, L-cysteine, L-cystine, D-cysteine, D-cystine, L-homocysteine, and L-homocystine.

21. The method of claim 18, wherein the coating is a stereospecific compound.

22. The method of claim 19, wherein the stereospecific compound comprises a mixture of D isomers and L isomers.

23. The coated metal electrode according to claim 19, wherein the stereospecific compound comprises a D isomer.

24. The coated metal electrode according to claim 19, wherein the stereospecific compound comprises an L isomer.

25. The method of claim 18, wherein a fill speed of the coated metal electrode is less than a fill speed of a corresponding uncoated metal electrode.