Electrochemical test sensor

• US 20080011616A1
• Filed: 07/05/2007
• Published: 01/17/2008
• Est. Priority Date: 07/11/2006
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Brown, Daniel V.
• Granted Patent: US 7,993,512 B2
• Time in Patent Office: Days
• US Class Current: 205/777.5
• CPC Class Codes: C12Q 1/001 Enzyme electrodes

Abstract

An electrochemical test sensor for detecting the concentration of an analyte in a sample. The electrochemical test sensor comprises a base that provides a flow path for the fluid test sample having a counter electrode and a working electrode on its surface in electrical communication with a detector of electrical current. The electrochemical test sensor further includes a reagent layer directly located on the surface of the working electrode. The reagent layer includes an enzyme that is adapted to react with the analyte. The electrochemical test sensor further comprises a lid adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of the sample thereto. The capillary space is formed with a three-dimensional portion of the lid.

Claims

1. An electrochemical test sensor for detecting the concentration of analyte in a fluid test sample, the electrochemical test sensor comprising:

a base that provides a flow path for the fluid test sample having on its surface a counter electrode and a working electrode in electrical communication with a detector of electrical current;

a reagent layer directly located on the surface of the working electrode, the reagent layer including an enzyme that is adapted to react with the analyte; and

a lid adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of fluid test sample thereto, the capillary space being formed with a three-dimensional portion of the lid.

2. The test sensor of claim 1, wherein the reagent layer is further located on the surface of the counter electrode.

3. The test sensor of claim 1, wherein the area of the working electrode adapted to interact with the analyte of the fluid test sample includes a main portion and at least one secondary portion extending therefrom.

4. The test sensor of claim 3, wherein the main portion of the working electrode has a first width in a first direction and the at least one secondary portion has a second width in the first direction, the first width being at least 2 times greater than the second width.

5. The test sensor of claim 4, wherein the main portion of the working electrode has a first height in a second direction and the at least one secondary portion has a second height in the second direction, the second direction being generally perpendicular to the first direction, the first height being from about 5 to about 15 times greater than the second height.

6. The test sensor of claim 3, wherein the at least one secondary portion of the working electrode is generally polygonal.

7. The test sensor of claim 6, wherein the main portion of the working electrode is generally polygonal.

8. The test sensor of claim 6, wherein the main portion of the working electrode is generally non-polygonal.

9. The test sensor of claim 1, wherein the capillary space is less than about 0.75 μ

L.

10. The test sensor of claim 1, wherein the capillary space is less than about 0.6 μ

L.

11. An electrochemical test sensor for detecting the concentration of analyte in a fluid test sample, the electrochemical test sensor comprising:

a base that provides a flow path for the fluid test sample having on its surface a counter electrode and a working electrode in electrical communication with a detector of electrical current, the working electrode includes a main portion and at least two secondary portions extending therefrom;

a reagent layer directly located on the surface of the working electrode, the reagent layer including an enzyme that is adapted to react with the analyte; and

a lid adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of fluid test sample thereto.

12. The test sensor of claim 11, wherein one of the secondary portions of the working electrode is in electrical communication with the detector.

13. The test sensor of claim 11, wherein the main portion of the working electrode is disposed between the at least two secondary portions of the working electrode, the at least two secondary portions of the working electrode being generally opposite from each other.

14. The test sensor of claim 12, wherein the area of the main portion of the working electrode is substantially larger than the area of the secondary portions of the working electrode.

15. An electrochemical test sensor for detecting the concentration of analyte in a fluid test sample, the electrochemical test sensor comprising:

a base that provides a flow path for the fluid test sample having on its surface a counter electrode and a working electrode in electrical communication with a detector of electrical current;

a reagent layer directly located on the surface of the working electrode, the reagent layer including an enzyme that is adapted to react with the analyte, the working electrode including a main portion having a first width in a first direction and further including at least one secondary portion extending from the main portion having a second width in the first direction, the first width being at least about 2 times greater than the second width; and

a lid adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of fluid test sample thereto.

16. The test sensor of claim 15, further including a spacer that is adapted to assist in forming the capillary opening, the spacer being located between the base and the lid.

17. The test sensor of claim 15, wherein the main portion of the working electrode has a first height in a second direction and the at least one secondary portion has a second height in the second direction, the second direction being generally perpendicular to the first direction, the first height being from about 5 to about 15 times greater than the second height.

18. The test sensor of claim 15, wherein the at least one secondary portion of the working electrode is generally polygonal.

19. The test sensor of claim 18, wherein the main portion of the working electrode is generally polygonal.

20. The test sensor of claim 18, wherein the main portion of the working electrode is generally non-polygonal.

21. The test sensor of claim 19, wherein the capillary space is less than about 0.75 μ

L.

22. The test sensor of claim 19, wherein the capillary space is less than about 0.6 μ

L.

23. A method for determining the concentration of an analyte in a fluid test sample with a test sensor, the method comprising the acts of:

providing a base that provides a flow path for the fluid test sample having on its surface a counter electrode and a working electrode in electrical communication with a detector of electrical current, the working electrode includes a main portion and at least two secondary portions extending therefrom, a reagent layer being directly located on the surface of the working electrode, the reagent layer including an enzyme that is adapted to react with the analyte, a lid being adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of fluid test sample thereto;

contacting the reagent layer with the fluid sample via the capillary space;

generating an electrical signal in the test sensor in response to the presence of the analyte; and

determining the concentration of the analyte from the electrical signal.

24. A method for determining the concentration of an analyte in a fluid sample with a test sensor, the method comprising the acts of:

providing an electrochemical test sensor comprising a base that provides a flow path for the fluid test sample having on its surface a counter electrode and a working electrode in electrical communication with a detector of electrical current, a reagent layer being directly located on the surface of the working electrode, the reagent layer including an enzyme that is adapted to react with the analyte, and a lid being adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of fluid test sample thereto, the capillary space being formed with a three-dimensional portion of the lid;

contacting the reagent layer with the fluid sample via the capillary space;

generating an electrical signal in the test sensor in response to the presence of the analyte; and

determining the concentration of the analyte from the electrical signal.

25. The method of claim 24, wherein the working electrode includes a main portion and at least two secondary portions adapted to interact with the liquid sample.

26. The method of claim 25, wherein the area of the main portion of the working electrode is at least 10 times the area of the at least two secondary portions of the working electrode adapted to interact with the fluid sample.

27. The method of claim 24, wherein the analyte is glucose.

28. The method of claim 24, wherein the capillary space is less than about 0.75 μ

L.