Lyotropic liquid crystal coated analyte monitoring device and methods of use

• US 8,666,470 B2
• Filed: 08/07/2012
• Issued: 03/04/2014
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Heller, Adam, Rowinski, Pawel, Feldman, Benjamin
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): CATINA, MICHAEL ANTHONY
• Application Number:
  US13/568,799
• Publication Number:
  US 20130066178A1
• Time in Patent Office: 574 Days
• Field of Search: 600345-347, 600/365
• US Class Current: 600/347
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

The present invention is directed to membranes composed liquid crystals having continuous aqueous channels, such as a lyotropic liquid crystal, including a cubic phase lyotropic liquid crystal, and to electrochemical sensors equipped with such membranes. The membranes are useful in limiting the diffusion of an analyte to a working electrode in an electrochemical sensor so that the sensor does not saturate and/or remains linearly responsive over a large range of analyte concentrations. Electrochemical sensors equipped with membranes of the present invention demonstrate considerable sensitivity and stability, and a large signal-to-noise ratio, in a variety of conditions.

Claims

1. A method of monitoring the concentration of an analyte, the method comprising:

positioning at least a portion of an electrochemical sensor beneath the surface of the skin of a subject, wherein the electrochemical sensor comprises;

a working electrode comprising a sensing layer comprising an analyte-responsive enzyme and a redox mediator in contact with the electrode and a non-crosslinked cubic phase lyotropic liquid crystal membrane disposed on top of the sensing layer; and

a counter electrode or reference electrode or a counter/reference electrode in communication with the working electrode;

applying a potential between the working electrode and the counter electrode to electrolyze the analyte and measuring a current from the applied potential; and

determining the concentration of the analyte from the measured current.

2. The method according to claim 1, wherein the analyte-responsive enzyme is a glucose-responsive enzyme.

3. The method according to claim 2, wherein the glucose-responsive enzyme is a glucose dehydrogenase.

4. The method according to claim 3, wherein the glucose dehydrogenase is an FAD-dependent glucose dehydrogenase.

5. The method according to claim 2, wherein the glucose-responsive enzyme is glucose oxidase.

6. The method according to claim 1, wherein the redox mediator comprises a ruthenium-containing complex or an osmium-containing complex.

7. The method according to claim 1, wherein the cubic phase lyotropic liquid crystal is substantially non-hydrolyzable in the presence of a lipase.

8. The method according to claim 7, wherein the cubic phase lyotropic liquid crystal comprises a compound of the formula:

9. The method according to claim 8, wherein the cubic phase lyotropic liquid crystal comprises Vitamin E acetate.

10. The method according to claim 1, wherein the sensor is adapted so that at least a portion of the sensor is positionable beneath the skin of a user.

11. The method according to claim 1, wherein the sensor comprises an anticlotting agent.

12. The method according to claim 11, wherein the anticlotting agent is heparin.

13. The method according to claim 11, wherein the cubic phase lyotropic liquid crystal comprises the anticlotting agent.

14. The method according to claim 1, wherein the cubic phase lyotropic liquid crystal membrane is adapted to limit the flux of glucose or lactate thereacross.

15. The method according to claim 1, wherein the analyte is glucose.