Small volume in vitro analyte sensor and methods of making

• US 8,425,743 B2
• Filed: 03/12/2010
• Issued: 04/23/2013
• Est. Priority Date: 10/08/1998
• Status: Expired due to Fees

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Feldman, Benjamin J., Heller, Adam, Heller, Ephraim, Mao, Fei, Vivolo, Joseph A., Funderburk, Jeffery V., Colman, Fredric C., Krishnan, Rajesh
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US12/723,169
• Publication Number:
  US 20100170793A1
• Time in Patent Office: 1,138 Days
• Field of Search: 20440301-40315, 205/777.5, 205/778, 205/792
• US Class Current: 204/403.02
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• 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 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49208 by assembling plural parts
• CPC Class Codes: Y10T 29/4921 with bonding
• CPC Class Codes: Y10T 29/49794 Dividing on common outline

Abstract

A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry; and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

Claims

1. A system comprising:

a biosensor comprising a first electrode, a second electrode, a third electrode, and a reagent layer including a reagent which reacts specifically with glucose in a sample solution, which biosensor measures the concentration of the glucose in the sample solution, said reagent layer being present in a sample chamber of the sensor and including glucose dehydrogenase having a coenzyme; and

a sensor reader configured to;

apply a first potential between the first and second electrodes to determine when the sample chamber is beginning to fill with sample;

apply a second potential between the first and third electrodes to determine with the sample chamber is substantially filled with sample;

apply a third potential between the first and second electrodes to electrolyze the glucose, thereby generating a glucose signal; and

measure the concentration of the glucose using the glucose signal.

2. A system as defined in claim 1, wherein the concentration of the glucose in the sample solution is measured using electrodes including at least a working electrode and a counter electrode, which electrodes are disposed in the sample chamber.

3. A system as defined in claim 2, wherein the reagent layer, including an electron carrier, is formed on the working electrode.

4. A system as defined in claim 2, wherein the working electrode and counter electrode are disposed in a facing configuration.

5. A system as defined in claim 2, wherein the working electrode and counter electrode are disposed in a coplanar configuration.

6. A system as defined in claim 2, wherein the working electrode and the counter electrode are separated by a closest distance that is no more than 100 μ

m.

7. A system as defined in claim 2, wherein the working electrode and the counter electrode are separated by a closest distance that is no more than 50 gm.

8. A system as defined in claim 2, wherein the biosensor comprises an indicator electrode disposed in the sample chamber.

9. A system as defined in claim 8, wherein the working electrode, counter electrode, and indicator electrode are disposed in a coplanar configuration.

10. A system as defined in claim 1 , wherein the reagent layer, including an electron carrier, is formed so that the electrodes are disposed in a diffusion area wherein the reagent of the reagent layer is dissolved in the sample solution and diffused.

11. A system as defined in claim 1 , wherein the biosensor comprises an electron carrier comprising:

a transition metal selected from the group consisting of osmium, ruthenium, iron, and cobalt;

two or more ligands coordinately bound to the transition metal, wherein at least one of the ligands is a heterocyclic nitrogen-containing bidentate ligand comprising

12. A system as defined in claim 11, wherein the transition metal is osmium.

13. A system as defined in claim 11, wherein R₁ is an alkyl.

14. A system as defined in claim 13, wherein R₁ is methyl.

15. A system as defined in claim 11, wherein at least one of the ligands is a unsubstituted or substituted pyridine.

16. A system as defined in claim 15, wherein at least one of the ligands is a monosubstituted pyridine.

17. A system as defined in claim 1, wherein the sample solution is blood obtained from the finger of a user.

18. A system as defined in claim 1, wherein the sample fluid is blood obtained from a region of a user having a lower nerve end density as compared to a fingertip.

19. A system as defined in claim 18, wherein the region of the user having a lower nerve end density as compared to a fingertip is selected from the group consisting of:

a forearm region, and a thigh region.

20. A system as defined in claim 1, wherein the reagent layer comprises an electron carrier comprising ferricyanide or ferrocyanide.

21. A system as defined in claim 1, wherein the sample chamber is sized to contain a volume of no more than 1 μ

L of the sample fluid.

22. A system as defined in claim 1, wherein the sample chamber is sized to contain a volume of no more than 0.5 μ

L of the sample fluid.