Biosensor membranes

• US 8,437,829 B2
• Filed: 08/20/2009
• Issued: 05/07/2013
• Est. Priority Date: 05/15/2001
• Status: Expired due to Term

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Inventors: Mao, Fei, Cho, Hyun
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US12/544,819
• Publication Number:
  US 20100213058A1
• Time in Patent Office: 1,356 Days
• Field of Search: 600/365, 600/345, 600/347, 20440305-40306, 427/2.13
• US Class Current: 600/347
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 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: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

Novel membranes comprising various polymers containing heterocyclic nitrogen groups are described. These membranes are usefully employed in electrochemical sensors, such as amperometric biosensors. More particularly, these membranes effectively regulate a flux of analyte to a measurement electrode in an electrochemical sensor, thereby improving the functioning of the electrochemical sensor over a significant range of analyte concentrations. Electrochemical sensors equipped with such membranes are also described.

Claims

1. An analyte sensor, comprising:

a working electrode, wherein the working electrode having;

a sensing layer comprising a first polymer and an analyte responsive enzyme positioned directly on top of the working electrode; and

a diffusion resistance layer comprising a second polymer positioned on top of the sensing layer, wherein the diffusion resistance layer comprises a crosslinker and wherein the second polymer comprises the formula;

2. The sensor of claim 1, wherein the analyte is glucose.

3. The sensor of claim 1, wherein the first polymer comprises heterocyclic nitrogen containing groups.

4. The sensor of claim 3, wherein the heterocyclic nitrogen-containing groups is a pyridine group.

5. The sensor of claim 1, wherein the analyte responsive enzyme is glucose oxidase.

6. The sensor of claim 1, wherein the sensing layer further comprises a redox mediator.

7. The sensor of claim 6, wherein the redox mediator is covalently bonded to the first polymer.

8. The sensor of claim 6, wherein the redox mediator forms a carbon-carbon or carbon-nitrogen covalent bond with the first polymer.

9. The sensor of claim 8, wherein the redox mediator is covalently bonded to the first polymer through one or more ligands of the mediator.

10. The sensor of claim 9, wherein the one or more ligands comprises a substituted or unsubstituted heterocyclic nitrogen-containing.

11. The sensor of claim 1, wherein the sensor is configured for subcutaneous implantation.

12. The sensor of claim 1, wherein A is negatively charged.

13. The sensor of claim 1, wherein A is a sulfonate group, carboxylate group or phosphate group.

14. The sensor of claim 1, wherein A is a sulfopropyl group, a sulfobutyl group, a carboxypropyl group or a carboxypentyl group.

15. The sensor of claim 1, wherein A has the formula L-G, where L is a C2-C12 linear or branched alkyl linker and G is a negatively charged carboxy or sulfonate.

16. The sensor of claim 1, wherein the crosslinker is a derivative of poly(ethylene glycol) or poly(propylene glycol).

17. The sensor of claim 1, wherein at least a part of the second polymer is hydrophilic.

18. The sensor of claim 1, wherein at least a part of the second polymer is hydrophobic.

19. The sensor of claim 1, wherein D is styrene or C1-C18 alkyl methacrylate.

20. The sensor of claim 1, wherein the second polymer has an average molecular weight above 50,000.

21. The sensor of claim 1, wherein the second polymer has an average molecular weight above 200,000.