Mediator for test sensor

• US 9,039,878 B2
• Filed: 12/17/2012
• Issued: 05/26/2015
• Est. Priority Date: 12/10/2007
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Marfurt, Karen L., Arndt, Henry C.
• Primary Examiner(s): Ball, J. Christopher
• Application Number:
  US13/717,024
• Publication Number:
  US 20130126350A1
• Time in Patent Office: 890 Days
• Field of Search: 544/36, 544/37, 20440301-40315
• US Class Current: 204/403.14
• CPC Class Codes: C07D 265/38 [b, e]-condensed with two six-membered rings
• CPC Class Codes: C07D 279/18 [b, e]-condensed with two six-membered rings
• CPC Class Codes: C07D 279/20 with hydrogen atoms directly attached to the ring nitrogen atom
• CPC Class Codes: C12Q 1/004 mediator-assisted
• 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 method of forming a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine mediator includes providing a first reactant including phenothiazine or phenoxazine, providing a first solvent, providing a second reactant and providing a second solvent. The first reactant, first solvent, second reactant and second solvent are combined to form a reactants solution. Sodium persulfate is added to the reactants solution to couple the first and second reactants resulting in a reaction solution including the 3-phenylimino-3H-phenothiazine or the 3-phenylimino-3H-phenoxazine mediator.

Claims

1. A test sensor including a base, the base including an enzyme adapted to react with an analyte, and a mediator, the mediator having a background current being less than 200 nA after being exposed to a temperature of 50°

C. for a duration of two weeks and further including a neutralizing agent, the neutralizing agent being present in an amount to obtain a pH in a range below 7 to about 5.5 in a mediator solution.

2. The test sensor of claim 1 wherein the neutralizing agent is sodium hydroxide.

3. The test sensor of claim 1 wherein the neutralizing agent is sodium bicarbonate.

4. The test sensor of claim 1 further including a buffer.

5. The test sensor of claim 4 wherein the buffer is sodium phosphate.

6. The test sensor of claim 1 wherein the test sensor is an electrochemical test sensor.

7. The test sensor of claim 1 wherein the test sensor is an optical test sensor.

8. The test sensor of claim 1 wherein the mediator is a 3-phenylimino-3H-phenothiazine mediator.

9. The test sensor of claim 1 wherein the neutralizing agent is sodium phosphate.

10. The test sensor of claim 1 wherein the neutralizing agent is present in an amount to obtain a pH in a range below 7 to about 6 in the mediator solution.

11. The test sensor of claim 1 wherein the neutralizing agent is present in an amount to obtain a pH of from about 5.5 to about 6 in the mediator solution.

12. A test sensor including a reagent, the reagent including a mediator and a neutralizing agent, the reagent having a % bias being within 2.4% between 0 and 400 mg/dL of glucose after being exposed to a temperature of 50°

C. for a duration of two weeks, the neutralizing agent being present in an amount to obtain a pH in a range below 7 to about 5.5 in a mediator solution.

13. The test sensor of claim 12 wherein the reagent includes a 3-phenylimino-3H-phenothiazine mediator.

14. The test sensor of claim 12 wherein the reagent further comprises glucose dehydrogenase (GDH) and a cellulose polymer.

15. The test sensor of claim 12 wherein the test sensor includes electrodes.

16. The test sensor of claim 12 wherein the % bias is within 1.8% between 0 and 100 mg/dL of glucose after being exposed to a temperature of 50°

C. for a duration of two weeks.

17. The test sensor of claim 12 wherein the neutralizing agent is present in an amount to obtain a pH in a range below 7 to about 6 in the mediator solution.

18. The test sensor of claim 12 wherein the neutralizing agent is present in an amount to obtain a pH of from about 5.5 to about 6 in the mediator solution.

19. A test sensor including electrodes and a reagent including glucose dehydrogenase (GDH), a mediator and a neutralizing agent, the reagent having a % bias being within 2.4% between 0 and 400 mg/dL of glucose after being exposed to a temperature of 50°

C. for a duration of two weeks, the neutralizing agent being present in an amount to obtain a pH in a range below 7 to about 5.5 in a mediator solution.

20. The test sensor of claim 19 wherein the reagent further includes 3-phenylimino-3H-phenothiazine mediator and a cellulose polymer.

21. The test sensor of claim 19 wherein the % bias is within 1.8% between 0 and 100 mg/dL of glucose after being exposed to a temperature of 50°

C. for a duration of two weeks.

22. The test sensor of claim 19 wherein the neutralizing agent is present in an amount to obtain a pH of from about 6 to about 7 in the mediator solution.

23. The test sensor of claim 19 wherein the neutralizing agent is present in an amount to obtain a pH of from about 5.5 to about 6 in the mediator solution.

24. A test sensor including a base, the base including an enzyme adapted to react with an analyte, and a 3-phenylimino-3H-phenothiazine mediator, the 3-phenylimino-3H-phenothiazine mediator having a background current being less than 200 nA after being exposed to a temperature of 50°

C. for a duration of two weeks and further including a neutralizing agent, the neutralizing agent being present in an amount to obtain a pH in a range below 7 to about 6 in a mediator solution.

25. The test sensor of claim 24 wherein the neutralizing agent is present in an amount to obtain a pH of from about 5.5 to about 6 in the mediator solution.

26. The test sensor of claim 24 wherein the neutralizing agent is sodium hydroxide.

27. The test sensor of claim 24 wherein the neutralizing agent is sodium bicarbonate.

28. The test sensor of claim 24 wherein the neutralizing agent is sodium phosphate.

29. The test sensor of claim 24 further including a buffer.

30. The test sensor of claim 29 wherein the buffer is sodium phosphate.

31. The test sensor of claim 24 wherein the test sensor is an electrochemical test sensor.

32. The test sensor of claim 24 wherein the test sensor is an optical test sensor.

33. A test sensor including a base, the base including an enzyme adapted to react with an analyte, and a 3-phenylimino-3H-phenothiazine mediator, the 3-phenylimino-3H-phenothiazine mediator having a background current being less than 200 nA after being exposed to a temperature of 50°

C. for a duration of two weeks and further including a neutralizing agent, the neutralizing agent being present in an amount to obtain a pH of about 6.1 in a mediator solution.

34. The test sensor of claim 33 wherein the neutralizing agent is sodium hydroxide.

35. The test sensor of claim 33 wherein the neutralizing agent is sodium bicarbonate.

36. The test sensor of claim 33 wherein the neutralizing agent is sodium phosphate.

37. The test sensor of claim 33 further including a buffer.

38. The test sensor of claim 37 wherein the buffer is sodium phosphate.

39. The test sensor of claim 33 wherein the test sensor is an electrochemical test sensor.

40. The test sensor of claim 33 wherein the test sensor is an optical test sensor.