Concentration Determination in a Diffusion Barrier Layer

• US 20070246357A1
• Filed: 04/11/2007
• Published: 10/25/2007
• Est. Priority Date: 10/12/2004
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Wu, Huan-Ping
• Granted Patent: US 8,317,988 B2
• Time in Patent Office: Days
• US Class Current: 204/403.10
• CPC Class Codes: B32B 2307/202 Conductive
• CPC Class Codes: B32B 38/18 Handling of layers or the laminate
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: C12Q 1/6813 Hybridisation assays
• CPC Class Codes: C12Q 1/6825 Nucleic acid detection involving sensors
• 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
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 27/3276 being a hybridisation with immobilised receptors using a FET type sensor G01N27/4145; concerning the hybridisation C12Q1/68
• CPC Class Codes: G01N 27/3277 being a redox reaction, e.g. detection by cyclic voltammetry voltammetry per se G01N27/42, G01N27/48
• CPC Class Codes: G01N 27/40 Semi-permeable membranes or partitions
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

The present invention relates to improved electrochemical biosensor strips and methods for determining the concentration of an analyte in a sample. By selectively measuring a measurable species residing in a diffusion barrier layer, to the substantial exclusion of the measurable species residing exterior to the diffusion barrier layer, measurement errors introduced by sample constituents, such as red blood cells, and manufacturing variances may be reduced.

Claims

1. An electrochemical sensor strip, comprising:

a base;

a first electrode on the base, the first electrode having at least one first layer on a first conductor, the first layer including a reagent layer; and

a second electrode on the base,

the at least one first layer having an average initial thickness selected in response to a read pulse applied to the first and second electrodes during an analyte analysis, where the read pulse substantially detects a measurable species within the first layer and substantially excludes from detection the measurable species external to the first layer.

2. The electrochemical sensor strip of claim 1, where the reagent layer includes an oxidoreductase enzyme and a binder.

3. The electrochemical sensor strip of claim 1, where the second electrode comprises the first layer on a second conductor.

4. The electrochemical sensor strip of claim 1, where the duration of the read pulse is less than 5 seconds.

5. The electrochemical sensor strip of claim 3, where the duration of the read pulse is less than 5 seconds.

6. The electrochemical sensor strip of claim 1, where the duration of the read pulse is less than 3 seconds.

7. The electrochemical sensor strip of claim 3, where the duration of the read pulse is less than 3 seconds.

8. The electrochemical sensor strip of claim 1, where the duration of the read pulse is from 0.05 second to 2.8 seconds.

9. The electrochemical sensor strip of claim 3, where the duration of the read pulse is from 0.05 second to 2.8 seconds.

10. The electrochemical sensor strip of any one of claim 1, where the duration of the read pulse is from 0.1 second to 1.5 seconds.

11. The electrochemical sensor strip of any one of claim 3, where the duration of the read pulse is from 0.1 second to 1.5 seconds.

12. The electrochemical sensor strip of claim 1, where the average initial thickness of the first layer is at least 1 μ

m.

13. The electrochemical sensor strip of claim 6, where the average initial thickness of the first layer is at least 1 μ

m.

14. The electrochemical sensor strip of claim 1, where the average initial thickness of the first layer is less than b 30 μ

m.

15. The electrochemical sensor strip of claim 6, where the average initial thickness of the first layer is less than 30 μ

m.

16. The electrochemical sensor strip of claim 1, where the average initial thickness of the first layer is from 1 to 30 μ

m.

17. The electrochemical sensor strip of claim 1, where the average initial thickness of the first layer is from 5 to 25 μ

m.

18. The electrochemical sensor strip of claim 6, where the average initial thickness of the first layer is from 5 to 25 μ

m.

19. The electrochemical sensor strip of claim 1, where at least 50% of the average initial thickness of the first layer remains on the conductor when the read pulse is applied.

20. The electrochemical sensor strip of claim 3, where at least 50% of the average initial thickness of the first layer remains on the conductor when the read pulse is applied.

21. The electrochemical sensor strip of claim 6, where at least 50% of the average initial thickness of the first layer remains on the conductor when the read pulse is applied.

22. The electrochemical sensor strip of claim 1, where from 70% to 80% of the average initial thickness of the first layer remains on the conductor when the read pulse is applied.

23. An electrochemical sensor strip, comprising:

a base;

a first electrode on the base, the first electrode having at least one first layer on a first conductor, the first layer including a reagent layer and a second layer between the first conductor and the first layer; and

a second electrode on the base, the second layer having an average initial thickness selected in response to a read pulse applied to the first and second electrodes during an analyte analysis, where the read pulse substantially detects a measurable species within the second layer and substantially excludes from detection the measurable species external to the second layer.

24-31. -31. (canceled)

32. A method of increasing the accuracy of quantitative analyte determination comprising:

receiving an analyte containing sample in an electrochemical sensor strip, the analyte containing sample having a liquid component;

applying a read pulse between a first conductor and a second conductor on a base of the electrochemical sensor, the read pulse applied for a duration that substantially detects a measurable species within a first layer on the first conductor and substantially excludes from detection the measurable species external to the first layer;

measuring a quantitative value of the analyte concentration in the sample in response to the read pulse.

33-42. -42. (canceled)