Enzyme Immobilization by Crosslinking

• US 20150001074A1
• Filed: 06/28/2013
• Published: 01/01/2015
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Liu, Zenghe
• Granted Patent: US 9,441,258 B2
• Time in Patent Office: Days
• US Class Current: 204/403.11
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/003 Functionalisation
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/40 Semi-permeable membranes or partitions

Abstract

An analyte sensor for the continuous or semi-continuous monitoring of physiological parameters and a method for making the analyte sensor are disclosed. In one aspect, the analyte sensor includes an electrode, a sensing layer in contact with a surface of the electrode, and a protective membrane. The sensing layer is a crosslinked, hydrophilic copolymer including poly(alkylene oxide) and poly(vinyl pyridine), and an analyte sensing component is immobilized within the crosslinked, hydrophilic copolymer. The protective membrane is a crosslinked, hydrophilic copolymer including alkylene oxide, vinyl pyridine and styrene units. The method involves the formation of a sensing layer on a surface of an electrode, followed by the formation of a protective membrane on a surface of the sensing layer.

Claims

1. An analyte sensor comprising:

a sensing layer in contact with a surface of an electrode, wherein the sensing layer comprises a first crosslinked, hydrophilic, diblock copolymer having an immobilized analyte sensing component, wherein the diblock copolymer comprises a first block of poly(alkylene oxide) and a second block of poly(vinyl pyridine); and

a protective membrane comprising a second crosslinked, hydrophilic, diblock copolymer, wherein the diblock copolymer comprises a poly(alkylene oxide) capped random copolymer of vinyl pyridine and styrene.

2. The sensor according to claim 1, wherein the first crosslinked, hydrophilic diblock copolymer having the formula:

3. The sensor according to claim 1, wherein the second crosslinked, hydrophilic diblock copolymer has the formula:

4. The sensor according to claim 1, wherein the sensing layer or the protective membrane has crosslinks of the formula:

5. The sensor according to claim 1, wherein the analyte sensing component is glucose oxidase.

6. The sensor according to claim 1, wherein the sensing layer or protective membrane is about 1 μ

m to about 5 μ

m in thickness.

7. The sensor according to claim 1, wherein the immobilized analyte sensing component is covalently bound, optionally through a linker, to the first crosslinked, hydrophilic, diblock copolymer.

8. The sensor according to claim 1, wherein the first crosslinked, hydrophilic diblock copolymer has the formula:

9. A method for manufacturing an analyte sensor, the method comprising:

forming a first solution of a first hydrophilic, diblock copolymer, a first crosslinking agent and an analyte sensing component, wherein the first hydrophilic, diblock copolymer comprises a first block of poly(alkylene oxide) and second block of poly(vinyl pyridine);

depositing the first solution onto a surface of an electrode;

curing the first solution to provide a sensing layer;

forming a second solution of a second hydrophilic, diblock copolymer and a second crosslinking agent, wherein the second hydrophilic, diblock copolymer comprises a poly(alkylene oxide) capped random copolymer of vinyl pyridine and styrene;

depositing the second solution onto a surface of the sensing layer; and

curing the second solution to provide a protective membrane.

10. The method of claim 9, wherein the first hydrophilic, diblock copolymer has the formula:

11. The method of claim 9, wherein the second hydrophilic, diblock copolymer has the formula:

12. The method of claim 9, wherein the first or second crosslinking agent has the formula:

13. The method of claim 9, wherein the sensing layer or the protective membrane is about 1 μ

m to about 5 μ

m in thickness.

14. The method of claim 9, wherein the analyte sensing component is glucose oxidase.

15. The method of claim 9, wherein the second solution comprises about 90% by weight second hydrophilic, diblock copolymer and about 10% by weight second crosslinking agent.

16. The method of claim 9, wherein the forming, depositing, and curing of the second solution is repeated to increase the thickness of the protective membrane.

17. The method of claim 9, wherein the amount of analyte sensing component is about 10% by weight to about 40% by weight of the first solution.

18. The method of claim 9, wherein the amount of first crosslinking agent is about 20% by weight to about 30% by weight of the first solution.

19. The method of claim 9, wherein the amount of first hydrophilic, diblock copolymer is about 20% by weight to about 70% by weight of the first solution.