Biosensor having improved hematocrit and oxygen biases

• US 7,501,053 B2
• Filed: 10/23/2002
• Issued: 03/10/2009
• Est. Priority Date: 10/23/2002
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Karinka, Shridhara Alva, Scott, W. James
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/278,657
• Publication Number:
  US 20040079653A1
• Time in Patent Office: 2,330 Days
• Field of Search: 20440301-40314, 205/777.5, 205/792
• US Class Current: 205/792
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

A biosensor that utilizes a mediator, i.e., an isomer of phenanthroline quinone, 1,10-phenanthroline-5,6-dione, and a metal ion, such as manganese, with an enzyme dependent upon NAD(P)⁺, such as, for example, glucose dehydrogenase, for improving the hematocrit bias and oxygen bias of biosensors. The electrodes of the biosensors employing this mediator and a metal ion provide an accurate clinical response over a hematocrit range that ranges from about 20% to about 70% and over an oxygen tension range that ranges from about 1 kPa to about 20 kPa.

Claims

1. A biosensor strip comprising:

(a) an electrode support;

(b) a first electrode disposed on said electrode support, said first electrode being a working electrode, said working electrode comprising a working ink deposited on an electrically conductive material, wherein said working ink comprises an enzyme and complex comprising a mediator and at least one heavier alkaline earth metal ion, wherein said mediator is 1,10-phenanthroline-5,6-dione or a derivative thereof;

(c) a second electrode disposed on said electrode support, said second electrode being a reference electrode; and

(d) a third electrode disposed on said electrode support, said third electrode being a counter electrode, said counter electrode comprising an electrically conductive material.

2. The biosensor strip of claim 1, wherein said at least one metal ion is selected from the group consisting of calcium, strontium, and barium ion.

3. The biosensor strip of claim 1, wherein said enzyme is selected from the group consisting of glucose oxidase and glucose dehydrogenase.

4. The biosensor strip of claim 1, wherein said enzyme is NAD(P)⁺-dependent dehydrogenase.

5. The biosensor strip of claim 1, further comprising a covering layer defining an enclosed space over said electrodes, said covering layer having an aperture for receiving a sample into said enclosed space.

6. The biosensor strip of claim 5, further comprising a least one layer of mesh interposed in the enclosed space between said covering layer and said electrodes.

7. The biosensor strip of claim 1, wherein said counter electrode is positioned relative to said working electrode and said reference electrode such that a liquid sample will contact said working electrode and said reference electrode prior to contacting said counter electrode.

8. A method for determining the concentration of an analyte in a sample of biological fluid, said method comprising the steps of:

(a) providing the biosensor strip of claim 1;

(b) inserting said biosensor strip into an analyte monitor;

(c) applying said biological fluid to said biosensor strip;

(d) applying a voltage at the working electrode with respect to the reference electrode;

(e) measuring the current flowing between the working electrode and the counter electrode; and

(f) correlating the current measured to the concentration of said analyte.

9. A biosensor strip comprising:

(a) an electrode support;

(b) a first electrode, said first electrode being a working electrode, said working electrode comprising working ink deposited on an electrically conductive material, wherein said working ink comprises an enzyme and a complex comprising a mediator and at least one heavier alkaline earth metal ion, wherein said mediator is 1,10-phenanthroline-5,6-dione or a derivative thereof;

(c) a second electrode, said second electrode being a dual-purpose reference/counter electrode.

10. The biosensor of claim 9, wherein said at least one heavier alkaline earth metal ion is selected from the group consisting of calcium, strontium, and barium ions.

11. The biosensor strip of claim 9, wherein said enzyme is selected from the group consisting of glucose oxidase and glucose dehydrogenase.

12. The biosensor strip of claim 9, wherein said enzyme is NAD(P)⁺-dependent dehydrogenase.

13. The biosensor strip of claim 9, wherein said electrode arrangement further includes a trigger electrode.

14. A method for determining the concentration of an analyte in a sample of biological fluid, said method comprising the steps of:

(a) providing the biosensor strip of claim 9;

(b) applying said biological fluid to said biosensor strip;

(c) inserting said biosensor strip into an analyte monitor;

(d) applying a voltage at the working electrode with respect to the dual-purpose reference/counter electrode;

(e) measuring the current flowing between the working electrode and the dual-purpose reference/counter electrode; and

(f) correlating the current measured to the concentration of said analyte.

15. A biosensor strip comprising:

(a) an electrode support;

(b) an electrode arrangement comprising at least two electrodes, one of said at least two electrodes being a working electrode, said working electrode disposed on said electrode support, said working electrode comprising a reaction layer comprising an enzyme and a complex comprising a mediator and at least one heavier alkaline earth metal ion, wherein said mediator is 1,10-phenanthroline-5,6-dione or a derivative thereof;

(c) another of said at least two electrodes being a counter electrode, said counter electrode disposed on said electrode support.

16. The biosensor strip of claim 15, wherein said at least one metal ion is selected from the group consisting of calcium, strontium, and barium ions.

17. The biosensor strip of claim 15, wherein said enzyme is selected from the group consisting of glucose oxidase and glucose dehydrogenase.

18. The biosensor strip of claim 15, wherein said enzyme is NAD(P)⁺-dependent dehydrogenase.

19. A method for determining the concentration of an analyte in a sample of biological fluid, said method comprising the steps of:

(a) providing the biosensor strip of claim 15;

(b) inserting said biosensor strip into an analyte monitor;

(c) applying said biological fluid to said biosensor strip;

(d) applying a voltage at the working electrode with respect to the counter electrode;

(e) measuring the current flowing between the working electrode and the counter electrode; and

(f) correlating the current measured to the concentration of said analyte.