Small volume in vitro analyte sensor

• US 9,341,591 B2
• Filed: 05/19/2014
• Issued: 05/17/2016
• 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): Van, Luan
• Assistant Examiner(s): Kaur, Gurpreet
• Application Number:
  US14/281,405
• Publication Number:
  US 20140251827A1
• Time in Patent Office: 729 Days
• US Class Current: 1/1
• 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 method for determining a blood glucose concentration in a blood sample, comprising:

contacting the blood sample with a sensor positioned in a blood glucose meter, wherein the sensor comprises;

a first electrode, a second electrode, and a third electrode;

a sample chamber for holding the blood sample, the sample chamber comprising the first electrode, the second electrode, and the third electrode; and

a glucose-responsive enzyme and a redox mediator disposed in the sample chamber;

applying a first potential between the first and second electrodes using the blood glucose meter and detecting a change in an electrical signal between the first and second electrodes to determine when the blood sample contacts the first and second electrodes, wherein detecting a change in an electrical signal between the first and second electrodes comprises detecting a voltage, current, resistance, capacitance, or combination thereof between the first and second electrodes;

applying a second potential between the first and third electrodes using the blood glucose meter and determining whether a change in an electrical signal occurs between the first and third electrodes to determine whether the blood sample contacts the first and third electrodes, wherein determining whether a change in an electrical signal occurs between the first and third electrodes comprises determining whether a voltage, current, resistance, capacitance, or combination thereof occurs between the first and third electrodes; and

subsequent to applying the second potential between the first and third electrodes, determining the blood glucose concentration only upon detecting the change in an electrical signal between the first and second electrodes and the change in an electrical signal between the first and third electrodes.

2. The method according to claim 1, wherein detecting the change in an electrical signal between the first and second electrodes comprises detecting the production of a current between the first and second electrodes.

3. The method according to claim 1, wherein determining whether a change in an electrical signal occurs between the first and third electrodes comprises determining whether a current is produced between the first and third electrodes.

4. The method according to claim 1, wherein the first, second and third electrodes are coplanar.

5. The method according to claim 1, wherein the sensor is a tip-fill sensor.

6. The method according to claim 1, wherein the sensor is a side-fill sensor.

7. The method according to claim 1, wherein the sample chamber is sized to contain a volume of no more than 1 μ

L of the blood sample.

8. The method according to claim 7, wherein the sample chamber is sized to contain a volume of no more than 0.5 μ

L of the blood sample.

9. The method according to claim 1, wherein the glucose-responsive enzyme is glucose oxidase or glucose dehydrogenase.

10. The method according to claim 1, wherein the method further comprises obtaining the blood sample from a finger of a subject.

11. The method according to claim 1, wherein the method further comprises obtaining the blood sample from a region of a subject having a lower nerve end density as compared to a fingertip.

12. The method according to claim 11, wherein the region of a subject 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.