Concentration determination in a diffusion barrier layer

• US 9,206,460 B2
• Filed: 09/03/2014
• Issued: 12/08/2015
• 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
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US14/476,592
• Publication Number:
  US 20150034498A1
• Time in Patent Office: 461 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 sensor strip, comprising:

a base;

a first electrode on the base, the first electrode having a 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, the second layer comprising an at least partially water-soluble polymeric material; and

a second electrode on the base.

2. The electrochemical sensor strip of claim 1, where an average initial thickness of the second layer is at least about 1 μ

m.

3. The electrochemical sensor strip of claim 1, where an average initial thickness of the second layer is from about 5 μ

m to about 25 μ

m.

4. The electrochemical sensor strip of claim 1, where the first layer includes an oxidoreductase enzyme and a mediator.

5. The electrochemical sensor strip of claim 4, where the reagent layer comprises a binder connecting the oxidoreductase enzyme and the mediator.

6. The electrochemical sensor strip of claim 1, where the second layer does not include a substantial amount of at least one of an oxidoreductase enzyme and a mediator.

7. The electrochemical sensor strip of claim 1, where the first layer comprises a binder forming a diffusion barrier layer.

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

9. An electrochemical sensor strip, comprising:

a first electrode on the base, the first electrode having a 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, the second layer including a polymeric material which comprises at least one of poly(ethylene oxide), carboxy methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, derivatives thereof, and combinations thereof; and

a second electrode on the base.

10. A method of quantitative analyte determination with an electrochemical sensor strip, the method comprising:

receiving an analyte-containing sample by the electrochemical sensor strip, the analyte-containing sample having a liquid component, the electrochemical sensor strip comprising a base with a first layer, a first conductor, and a second conductor on the base, the first layer including a reagent layer and a second layer between the first conductor and the first layer, the second layer comprising an at least partially water-soluble polymeric material;

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

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

11. The method of claim 10, where the read pulse comprises an electric potential.

12. The method of claim 10, where the analyte-containing sample resides in a gap formed between the base and a lid of the electrochemical sensor strip, the gap having a volume of about 1 mL to about 10 mL.

13. The method of claim 10, further comprising applying an initial pulse and a time delay before the read pulse.

14. The method of claim 13, where the initial pulse is from about 1 second to about 4 seconds.

15. The method of claim 13, where the time delay is from about 2 seconds to about 4 seconds.

16. The method of claim 10, where the first layer includes an oxidoreductase enzyme, a mediator, and a binder connecting the oxidoreductase enzyme and the mediator.

17. The method of claim 10, where the first layer comprises a binder forming a diffusion barrier layer.

18. The method of claim 10, where an average initial thickness of the second layer is at least about 1 μ

m.

19. The method of claim 10, where an average initial thickness of the second layer is about 5 μ

m to about 25 μ

m.

20. A method of quantitative analyte determination with an electrochemical sensor strip, the method comprising:

receiving an analyte-containing sample by the electrochemical sensor strip, the analyte-containing sample having a liquid component, the electrochemical sensor strip comprising a base with a first layer, a first conductor, and a second conductor on the base, the first layer including a reagent layer and a second layer between the first conductor and the first layer, the second layer comprising at least one of poly(ethylene oxide), carboxy methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, derivatives thereof, and combinations thereof;

applying a read pulse between the first conductor and the second conductor of the electrochemical sensor strip, the read pulse applied for a duration that substantially detects a measurable species within the first layer on the first conductor; and

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