Concentration determination in a diffusion barrier layer

• US 9,546,974 B2
• Filed: 11/03/2015
• Issued: 01/17/2017
• Est. Priority Date: 10/12/2004
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Inventors: Wu, Huan-Ping
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US14/931,346
• Publication Number:
  US 20160054255A1
• Time in Patent Office: 441 Days
• US Class Current: 1/1
• 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 test sensor, comprising:

a base;

a first electrode structure coupled to the base, the first electrode structure including a first layer structure coupled to a first conductor, the first layer structure including a first reagent layer and a diffusion barrier layer, the diffusion barrier layer having a porous space with an internal volume, the porous space configured to diffuse and store a measurable species into the internal volume; and

a second electrode structure coupled to the base.

2. The electrochemical test sensor of claim 1, wherein the porous space includes pores configured to diffuse a fluid sample with the measurable species into the internal volume of the diffusion barrier layer while excluding physically larger constituents of the fluid sample.

3. The electrochemical test sensor of claim 1, wherein a first portion of the measurable species external to the diffusion barrier layer diffuses to the first conductor at a first rate, and the porous space includes pores configured to diffuse a second portion of the measurable species from the internal volume to the first conductor at a second rate different than the first rate.

4. The electrochemical test sensor of claim 1, wherein the diffusion barrier layer is integrally formed with the first reagent layer.

5. The electrochemical test sensor of claim 1, wherein the diffusion barrier layer comprises an at least partially water-soluble polymeric binder material.

6. The electrochemical test sensor of claim 1, wherein the diffusion barrier layer has an average initial thickness of from about 8 μ

m to about 15 μ

m.

7. The electrochemical test sensor of claim 1, wherein the second electrode structure includes a second reagent layer coupled to a second conductor.

8. The electrochemical test sensor of claim 1, wherein the first conductor includes a first surface conductor on a first main conductor.

9. The electrochemical test sensor of claim 1, wherein an average initial thickness of the first layer structure is less than about 30 μ

m.

10. The electrochemical test sensor of claim 1, wherein the first reagent layer includes an oxidoreductase enzyme and a mediator.

11. The electrochemical test sensor of claim 10, wherein the first reagent layer further comprises a binder connecting the oxidoreductase enzyme and the mediator.

12. The electrochemical test sensor of claim 10, wherein the first reagent layer does not include a substantial amount of the oxidoreductase enzyme.

13. An electrochemical test sensor for measuring an analyte in a fluid sample, the electrochemical test sensor comprising:

an electrically insulating base;

a first electrode structure mounted on the base, the first electrode structure comprising a diffusion barrier layer mounted on a first conductor, and a first reagent layer mounted on the diffusion barrier layer, the diffusion barrier layer comprising an at least partially water-soluble polymeric material having a porous space with an internal volume configured to store therein a measurable species, the porous space configured to diffuse a fluid sample with the measurable species into the internal volume; and

a second electrode structure mounted on the base, the second electrode structure having a second reagent layer mounted on a second conductor.

14. A method of assembling an electrochemical test sensor, the method comprising:

receiving a base;

coupling a first electrode structure to the base, the first electrode structure including a first layer structure coupled to a first conductor, the first layer structure including a first reagent layer and a diffusion barrier layer, the diffusion barrier layer having a porous space with an internal volume, the porous space configured to diffuse and store a measurable species into the internal volume; and

coupling a second electrode structure to the base.

15. The method of claim 14, wherein the porous space includes pores configured to diffuse a fluid sample with the measurable species into the internal volume of the diffusion barrier layer while excluding physically larger constituents of the fluid sample.

16. The method of claim 14, wherein a first portion of the measurable species external to the diffusion barrier layer diffuses to the first conductor at a first rate, and the porous space includes pores configured to diffuse a second portion of the measurable species from the internal volume to the first conductor at a second rate different than the first rate.

17. The method of claim 14, wherein the diffusion barrier layer is integrally formed with the first reagent layer.

18. The method of claim 14, wherein the diffusion barrier layer comprises an at least partially water-soluble polymeric binder material.

19. The method of claim 14, wherein the diffusion barrier layer has an average initial thickness of about 8 μ

m to about 15 μ

m.

20. The method of claim 14, wherein the second electrode structure includes a second reagent layer coupled to a second conductor.