In vitro analyte sensor, and methods

• US 20070056858A1
• Filed: 09/12/2005
• Published: 03/15/2007
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Chen, Ting, Ghesquiere, Alexander
• Granted Patent: US 8,298,389 B2
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

In vitro electrochemical sensor that provide accurate and repeatable analysis of a sample of biological fluid are provided. In some embodiments, the sensors have a measurement zone that has a volume less than the volume of the sample chamber. The measurement zone could have a volume of no more than about 0.2 μL.

Claims

1. A sensor for determining the concentration of an analyte in a sample, the sensor comprising a sample chamber having a volume,

wherein the sensor is configured to determine the concentration of the analyte in a sample that partially fills the sample chamber.

2. The sensor according to claim 1 further comprising a measurement zone within the sample chamber, the measurement zone having a volume less than the volume of the sample chamber.

3. The sensor according to claim 2 wherein the measurement zone has an axial length that is less than an axial length of the sample chamber.

4. The sensor according to claim 3 wherein the measurement zone has a thickness that is no more than 10% of the axial length of the measurement zone.

5. The sensor according to claim 2 wherein the sample chamber has a volume of no more than 1 μ

L and the measurement zone has a volume of no more than 0.2 μ

L.

43. A kit comprising:

(a) at least one analyte sensor according to claim 1;

and

(b) at least one of;

(i) a meter configured for operably receiving the analyte sensor;

or

(ii) a lancing device.

44. A system for determining analyte concentration in a sample, the system comprising:

(a) an analyte sensor according to claim 1 for receiving the sample to be tested; and

(b) a meter operably connected to the sensor.

6. A method of determining the concentration of an analyte in a sample in biological fluid, the method comprising:

(a) contacting a sample of biological fluid with a sample chamber of an analyte sensor, the sample chamber having a volume;

(b) filling only a portion of the sample chamber with the sample; and

(c) determining the analyte concentration in the sample.

7. The method according to claim 6 wherein determining the analyte concentration in the sample comprises:

(a) determining the analyte concentration in the sample using only a portion of the sample in the sample chamber.

8. The method according to claim 6 wherein filling only a portion of the sample chamber comprises:

(a) filling a measurement zone, the measurement zone having a volume less than the volume of the sample chamber.

9. The method according to claim 8 further comprising:

(a) prior to determining the analyte concentration in the sample, determining that a sufficient amount of sample is in the measurement zone.

10. The method according to claim 9 wherein determining that a sufficient amount of sample is in the measurement zone comprises:

(a) determining that a sufficient amount of sample is in the measurement zone using an indicator electrode.

11. The method according to claim 6 wherein prior to determining the analyte concentration in the sample, the method comprises:

(a) maintaining the sample in a fixed position.

12. The method according to claim 11 further comprising:

(a) verifying sample flow has stopped prior to determining the analyte concentration.

13. The method according to claim 12 wherein verifying sample flow has stopped prior to determining the analyte concentration comprises:

(a) verifying sample flow has stopped using an indicator electrode.

14. The method according to claim 6 wherein determining the analyte concentration in the sample comprises:

(a) determining the analyte concentration in the sample using coulometry.

15. The method according to claim 6 wherein determining the analyte concentration in the sample comprises:

(a) determining the analyte concentration in the sample using amperometry.

16. A sensor for determining the concentration of an analyte in a sample, the sensor comprising:

(a) a sample chamber having a volume of no more than 1 μ

L; and

(b) a measurement zone within the sample chamber, the measurement zone having a volume about 75% or less than the volume of the sample chamber.

17. The sensor according to claim 16 further comprising a working electrode and a counter electrode having a distance therebetween, the electrodes being in the measurement zone, wherein the distance between the working electrode and the counter electrode is less than about 10% of an axial length of the measurement zone.

18. The sensor according to claim 17, wherein the distance between the working electrode and the counter electrode is less than about 5% of the axial length of the measurement zone.

19. The sensor according to claim 17 wherein the working electrode and the counter electrode are opposed to each other.

20. The sensor according to claim 17 further comprising a spacer having a thickness, wherein the distance between the working electrode and the counter electrode is the thickness of the spacer.

21. The sensor according to claim 16, wherein the sample chamber has a volume of no more than about 0.5 μ

L.

22. The sensor according to claim 16, wherein the measurement zone has a volume no more than about 0.2 μ

L.

23. The sensor according to claim 16, wherein the measurement zone has a volume of no more than about 0.1 μ

L.

24. The sensor according to claim 16, wherein the measurement zone has a volume of no more than about 0.05 μ

L.

25. The sensor according to claim 16, wherein the measurement zone has a volume of no more than about 0.03 μ

L.

26. A sensor for determining the concentration of an analyte in a sample, the sensor comprising:

(a) a sample chamber having a volume;

(b) a measurement zone within the sample chamber, the measurement zone having an axial length and a volume less than the volume of the sample chamber; and

(c) a working electrode and a counter electrode having a distance therebetween, the electrodes being in the measurement zone;

wherein the distance between the working electrode and the counter electrode is less than 10% of the axial length of the measurement zone.

27. The sensor according to claim 26, wherein the distance between the working electrode and the counter electrode is less than about 5% of the axial length of the measurement zone.

28. The sensor according to claim 26 wherein the working electrode and the counter electrode are opposed to each other.

29. The sensor according to claim 28 further comprising a spacer having a thickness, wherein the distance between the working electrode and the counter electrode is the thickness of the spacer.

30. The sensor according to claim 26, wherein the measurement zone has a volume of no more than about 1 μ

L.

31. The sensor according to claim 26, wherein the measurement zone has a volume of no more than about 0.2 μ

L.

32. The sensor according to claim 26, wherein the measurement zone has a volume of no more than about 0.1 μ

L.

33. The sensor according to claim 26, wherein the measurement zone has a volume of no more than about 0.05 μ

L.

34. The sensor according to claim 26 further comprising at least one indicator electrode.

35. A sensor for determining the concentration of an analyte in a sample, the sensor strip comprising:

(a) a first substrate and a second substrate;

(b) a sample chamber present between the first substrate and the second substrate, the sample chamber having an inlet, a volume of no more than about 1 μ

L, and having therein;

(c) a working electrode on the first substrate;

(d) a counter electrode on the second substrate opposed to the working electrode, together the working electrode and the counter electrode having a distance therebetween and forming an electrode overlap, with the distance therebetween being no more than an axial length of the overlap;

(e) an indicator electrode on one of the first substrate or the second substrate, the working electrode positioned between the indicator electrode and the inlet; and

(f) a measurement zone having a volume less than the volume of the sample chamber, the measurement zone defined by the electrode overlap.

36. The sensor according to claim 35, wherein the counter electrode has an axial length greater than an axial length of the working electrode.

37. The sensor according to claim 35 wherein the volume of the measurement zone is about 75% or less of the volume of the sample chamber.

38. The sensor according to claim 35, wherein the measurement zone has a volume of no more than about 0.2 μ

L.

39. The sensor according to claim 35, wherein the measurement zone has a volume of no more than about 0.15 μ

L.

40. The sensor according to claim 35, wherein the measurement zone has a volume of no more than about 0.1 μ

L.

41. The sensor according to claim 35, wherein the measurement zone has a volume of no more than about 0.05 μ

L.

42. The sensor according to claim 35, wherein the distance between the working electrode and the counter electrode is no more than 0.2 mm.