Electrode system for measuring an analyte concentration under in-vivo conditions

• US 10,390,743 B2
• Filed: 06/17/2016
• Issued: 08/27/2019
• Est. Priority Date: 09/11/2008
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Rieger, Ewald, Mischler, Reinhold, Quarder, Ortrud, Staib, Arnulf, Kamecke, Ulrike, Gillen, Ralph
• Primary Examiner(s): Jang, Christian
• Assistant Examiner(s): Alter, Mitchell E
• Application Number:
  US15/185,158
• Publication Number:
  US 20160296151A1
• Time in Patent Office: 1,166 Days
• Field of Search: 600345
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

Electrode systems are disclosed for measuring the concentration of an analyte under in-vivo conditions, where such systems include a counter electrode having an electrical conductor, a working electrode having an electrical conductor on which an enzyme layer containing immobilized enzyme molecules for catalytic conversion of the analyte is arranged, and a diffusion barrier that slows the diffusion of the analyte from body fluid surrounding the electrode system to enzyme molecules. The enzyme layer is in the form of multiple fields that are arranged on the conductor of the working electrode at a distance from each other.

Claims

1. An electrode system for measuring an analyte concentration under in-vivo conditions, the system comprising:

a counter electrode having an electrical conductor;

a working electrode having an electrical conductor on which an enzyme layer containing immobilized enzyme molecules for catalytic conversion of the analyte is arranged, wherein the enzyme layer is in the form of multiple, discontinuous, individual fields that are arranged on the conductor of the working electrode at a distance from each other to reduce transient local effects; and

a diffusion barrier that slows the diffusion of the analyte from body fluid surrounding the electrode system to the enzyme molecules.

2. The electrode system of claim 1, further comprising a substrate wherein the electrical conductor of the working electrode and the electrical conductor of the counter electrode are arranged on the substrate.

3. The electrode system of claim 1, wherein the multiple fields are arranged in one or more rows or series.

4. The electrode system of claim 3, wherein the multiple fields are arranged at a distance from one another on the electrical conductor of the working electrode so that the multiple fields are separate from each other.

5. The electrode system of claim 1, wherein between the fields of the enzyme layer, the conductor of the working electrode is covered by an insulation layer.

6. The electrode system of claim 1, wherein at least two of the fields of the enzyme layer are at least 3 mm distant from each other.

7. The electrode system of claim 1, wherein a distance of at least 0.3 mm exists between neighboring fields of the enzyme layer.

8. The electrode system of claim 1, wherein the fields of the enzyme layer each extend less than 2 mm in two directions that are perpendicular to each other.

9. The electrode system of claim 1, wherein the diffusion barrier is a layer covering the enzyme layer.

10. The electrode system of claim 1, wherein the diffusion barrier is a mixture of at least two different acrylates.

11. The electrode system of claim 10, wherein at least one of the acrylates is a copolymer.

12. The electrode system of claim 11, wherein the enzyme interacts with a catalytic redox mediator contained in the enzyme layer and reduces or prevents an oxygen dependence of the catalytic conversion of the analyte.

13. The electrode system of claim 12, wherein the catalytic redox mediator converts hydrogen peroxide.

14. The electrode system of claim 13, wherein the catalytic redox mediator effects a direct electron transfer.

15. The electrode system of claim 1, wherein the enzyme layer is covered by a spacer.

16. The electrode system of claim 1, wherein the spacer covers the working electrode and the counter electrode in the form of a continuous layer.

17. The electrode system of claim 1, wherein the conductor of the working electrode narrows between the enzyme layer fields and the conductor of the counter electrode has a contour that follows the course of the conductor of the working electrode.

18. A sensor comprising:

an electrode system comprising;

a counter electrode having an electrical conductor;

a working electrode having an electrical conductor on which an enzyme layer containing immobilized enzyme molecules for catalytic conversion of the analyte is arranged, wherein the enzyme layer is in the form of multiple, discontinuous, individual fields that are arranged on the conductor of the working electrode at a distance from each other to reduce transient local effects;

a diffusion barrier that slows the diffusion of the analyte from body fluid surrounding the electrode system to the enzyme molecules,

a potentiostat connected to the electrode system, and

an amplifier for amplifying measuring signals of the electrode system.

19. The sensor of claim 18, wherein the working and counter electrodes of the electrode system are arranged on a substrate that carries the potentiostat or are attached on a circuit board that carries the potentiostat.

20. An electrode system for measuring an analyte concentration under in-vivo conditions, the system comprising:

a counter-electrode having an electrical conductor;

a working electrode having an electrical conductor on which an enzyme layer containing immobilized enzyme molecules for catalytic conversion of the analyte is arranged, wherein the enzyme layer is provided over a distance of at least 3 mm in the form of multiple, discontinuous, individual fields that are arranged on the conductor of the working electrode at a distance from each other; and

a diffusion barrier that slows the diffusion of the analyte from body fluid surrounding the electrode system to the enzyme molecules.