Chemically reactive enzyme immobilization

• US 9,551,680 B2
• Filed: 06/28/2013
• Issued: 01/24/2017
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Inventors: Liu, Zenghe, Linhardt, Jeffrey George
• Primary Examiner(s): Ball, J. Christopher
• Application Number:
  US13/930,821
• Publication Number:
  US 20150001072A1
• Time in Patent Office: 1,306 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/6821 Eye
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• 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

Abstract

An analyte sensor for the continuous or semi-continuous monitoring of physiological parameters and a method for making the analyte sensor are disclosed. The analyte sensor includes a crosslinked, hydrophilic copolymer sensing layer in contact with a surface of an electrode, where the sensing layer includes methacrylate-derived backbone chains having covalent bonds to an analyte sensing component. The method includes combining the precursor components of the sensing layer, depositing the combined mixture on a surface of an electrode, and curing the deposited mixture.

Claims

1. An analyte sensor comprising:

a sensing layer in contact with a surface of an electrode, wherein the sensing layer comprises;

backbone chains comprising

first methacrylate-derived monomeric units, each of which is covalently bound to an analyte sensing component through a hydrophilic linker, and

second methacrylate-derived monomeric units;

hydrophilic crosslinks between the second methacrylate-derived units in different backbone chains; and

third methacrylate-derived monomeric units, each having a hydrophilic side chain,

wherein the third methacrylate-derived units are present in at least one of the sensing layer or an additional layer provided on the sensing layer; and

wherein the sensing layer has a thickness of about 10 μ

m to about 30 μ

m.

2. The sensor of claim 1, wherein the third methacrylate-derived monomeric units are present in the sensing layer.

3. The sensor of claim 1, wherein

the third methacrylate-derived monomeric units are present in an additional layer, and

the additional layer is a protective membrane comprising:

backbone chains comprising;

third methacrylate-derived monomeric units, each unit having a hydrophilic side chain, and

fourth methacrylate-derived monomeric units; and

hydrophilic crosslinks between the fourth methacrylate-derived units in different backbone chains.

4. The sensor of claim 1, wherein the first methacrylate-derived monomeric units have the structure of formula (I):

5. The sensor of claim 1, wherein the first methacrylate-derived monomeric units have the structure of formula (Ia):

6. The sensor of claim 1, wherein the third methacrylate-derived units have the structure of formula (IIa):

7. The sensor of claim 1, wherein the third methacrylate-derived units have the structure:

8. The sensor of claim 1, wherein the third methacrylate-derived units have the structure of formula (IIb):

9. The sensor of claim 1, wherein the hydrophilic crosslinks between the second or fourth methacrylate-derived units in different backbone chains comprise one or more alkylene oxide units.

10. The sensor of claim 1, wherein the hydrophilic crosslinks between the second or fourth methacrylate-derived units in different backbone chains have the structure of formula (IIIa):

11. The sensor of claim 1, wherein the hydrophilic crosslinks between the second or fourth methacrylate-derived units in different backbone chains have the structure of formula (IIIa):

12. The sensor of claim 1, wherein the hydrophilic crosslinks between the second or fourth methacrylate-derived units in different backbone chains are derived from the di(ethylene glycol) portion of di(ethylene glycol) dimethacrylate.

13. The sensor of claim 1, wherein the analyte sensing component comprises glucose oxidase.

14. The sensor of claim 2, wherein the sensing layer comprises:

first methacrylate-derived monomeric units having the structure of formula (I);

15. The analyte sensor of claim 3, wherein

the sensing layer comprises:

first methacrylate-derived monomeric units having the structure of formula (I);

16. A method of making an analyte sensor, comprising:

forming a first mixture comprising a first methacrylate monomer, a first dimethacrylate monomer, and a first initiator, wherein the first methacrylate monomer has a covalent bond to an analyte sensing component;

depositing the first mixture on a surface of an electrode;

curing the deposited first mixture to provide a sensing layer; and

including a second methacrylate monomer in at least one of the first mixture or a second mixture deposited on the sensing layer,

wherein the sensing layer has a thickness of about 10 μ

m to about 30 μ

m.

17. The method of claim 16, wherein the first mixture further comprises the second methacrylate monomer.

18. The method of claim 16, further comprising:

forming a second mixture comprising the second methacrylate monomer, a second dimethacrylate monomer, and a second initiator;

depositing the second mixture onto the sensing layer; and

curing the deposited second mixture to provide a protective membrane on the sensing layer.

19. The method of claim 16, wherein the first methacrylate monomer has the structure of formula (IV):

20. The method of claim 16, wherein the first methacrylate monomer have the structure of formula (IVa):

21. The method of claim 16 or 18, wherein the second methacrylate monomer has the structure of formula (Va):

22. The method of claim 16 or 18, wherein the second methacrylate monomer has the structure:

23. The method of claim 16 or 18, wherein the second methacrylate monomer has the structure of formula (Va):

24. The method of claim 16 or 18, wherein the first or second dimethacrylate monomer comprises alkylene oxide units.

25. The method of claim 16 or 18, wherein the first or second dimethacrylate monomer has a structure of formula (VI):

26. The method of claim 16 or 18, wherein the first or second dimethacrylate monomer has a structure of formula (VI):

27. The method of claim 16 or 18, wherein the first or second dimethacrylate monomer is di(ethylene glycol) dimethacrylate.

28. The method of claim 16, wherein the analyte sensing component comprises glucose oxidase.

29. The method of claim 16 or 18, wherein curing the deposited first or second mixture comprises exposing the deposited first or second mixture to ultraviolet light.

30. The method of claim 16 or 18, wherein first or second initiator is 2,2-dimethoxy-2-phenylacetophenone.