Biosensor membranes composed of polymers containing heterocyclic nitrogens

• US 20030042137A1
• Filed: 05/14/2002
• Published: 03/06/2003
• Est. Priority Date: 05/15/2001
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Original Assignee: Therasense Incorporated (Abbott Laboratories)
• Inventors: Cho, Hyun, Mao, Fei
• Granted Patent: US 6,932,894 B2
• Time in Patent Office: Days
• US Class Current: 204/403.01
• 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. A membrane for use in an electrochemical sensor, comprising:

a crosslinker; and

a polymer having the formula;

wherein the solid horizontal line represents a polymer backbone;

A is an alkyl substituted with a water-soluble constituent;

D is selected from a group consisting of phenylalkyl, alkoxystyrene, hydroxyalkyl, alkoxyalkyl, alkoxycarbonylalkyl, a poly(ethylene glycol)-containing constituent, and a polyhydroxyl-containing constituent; and

each of n, l, p and q is independently a positive number.

2. The membrane of claim 1, wherein A is negatively charged.

3. The membrane of claim 1, wherein A is selected from a group consisting of a sulfonate, a carboxylate, and a phosphate.

4. The membrane of claim 1, wherein A is selected from a group consisting of sulfopropyl, sulfobutyl, carboxypropyl, and carboxypentyl.

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

6. The membrane of claim 5, wherein L is substituted with an aryl, alkoxy, alkenyl, alkynyl, —

F, —

Cl, —

OH, aldehyde, ketone, ester, or amide.

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

8. The membrane of claim 1, wherein the polymer has a formula selected from a group consisting of:

9. The membrane of claim 1, wherein an average molecular weight of the polymer is above about 50,000.

10. The membrane of claim 1, wherein an average molecular weight of the polymer is above about 200,000.

11. The membrane of claim 1, wherein an average molecular weight of the polymer is above about 1,000,000.

12. The membrane of claim 1, wherein the polymer further comprises a B-containing copolymer such that the polymer has the formula:

13. The membrane of claim 12, wherein B is selected from a group consisting of a chelator, a negatively charged constituent, a hydrophobic hydrocarbon constituent, a hydrophilic hydroxyl or polyhydroxy constituent, a silicon polymer, and a poly(ethylene glycol).

14. The membrane of claim 12, wherein B is a poly(ethylene glycol) having a molecular weight of from about 100 to about 20,000.

15. The membrane of claim 12, wherein the polymer has a formula selected from a group consisting of:

16. The membrane of claim 12, wherein [n/(n+m+l+p)]×

100% is from about 1% to about 25%.

17. The membrane of claim 12, wherein [m/(n+m+l+p)]×

100% is from about 1% to about 15%.

18. The membrane of claim 12, wherein [l/(n+m+l+p)]×

100% is from about 20% to about 90%.

19. The membrane of claim 12, wherein [p/(n+m+l+p)]×

100% is from about 1% to about 50%.

20. The membrane of claim 1 or 12, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of pyridine, imidazole, oxazole, thiazole, pyrazole, and any derivative thereof.

21. The membrane of claim 1 or 12, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylimidazole, and 4-vinylimidazole.

22. The membrane of claim 1 or 12 sufficient to limit a flux of glucose or lactate thereacross.

23. The membrane of claim 1 or 12 sufficient to limit a flux of glucose or lactate thereacross in vivo.

24. The membrane of claim 1 or 12, wherein the crosslinker comprises at least one epoxide reactive group.

25. The membrane of claim 1 or 12, wherein the crosslinker has a molecular weight of from about 200 to about 2000.

26. The membrane of claim 1 or 12, wherein the crosslinker is a derivative of poly(ethylene glycol) or poly(propylene glycol).

27. The membrane of claim 1 or 12, wherein a weight ratio of the polymer to the crosslinker is from about 4:

1 to about 32;

1.

28. The membrane of claim 1 or 12, wherein a weight ratio of the polymer to the crosslinker is from about 8:

1 to about 16;

1.

29. The membrane of claim 1, further comprising a layer of poly(ethylene glycol).

30. An electrochemical sensor, comprising:

a working electrode comprising;

a sensing layer in contact with a conductive material of the electrode;

a membrane disposed over the sensing layer, the membrane comprising a crosslinker and a polymer having the formula;

wherein the solid horizontal line represents a polymer backbone;

A is an alkyl substituted with a water-soluble constituent;

D is selected from a group consisting of phenylalkyl, alkoxystyrene, hydroxyalkyl, alkoxyalkyl, alkoxycarbonylalkyl, a poly(ethylene glycol)-containing constituent, and a polyhydroxyl-containing constituent; and

each of n, l, p and q is independently a positive number; and

a counter electrode in electrochemical communication with the working electrode.

31. The electrochemical sensor of claim 30, wherein A is negatively charged.

32. The electrochemical sensor of claim 30, wherein A is selected from a group consisting of a sulfonate, a carboxylate, and a phosphate.

33. The electrochemical sensor of claim 30, wherein A is selected from a group consisting of sulfopropyl, sulfobutyl, carboxypropyl, and carboxypentyl.

34. The electrochemical sensor of claim 30, wherein A is of the formula L-G, where L is a C2-C12 linear or branched alkyl linker and G is a negatively charged carboxy or sulfonate.

35. The electrochemical sensor of claim 34, wherein L is substituted with an aryl, alkoxy, alkenyl, alkynyl, —

F, —

Cl, —

OH, aldehyde, ketone, ester, or amide.

36. The electrochemical sensor of claim 30, wherein D is styrene or C1-C18 alkyl methacrylate.

37. The electrochemical sensor of claim 30, wherein the polymer has a formula selected from a group consisting of:

38. The electrochemical sensor of claim 30, wherein an average molecular weight of the polymer is above about 50,000.

39. The electrochemical sensor of claim 30, wherein an average molecular weight of the polymer is above about 200,000.

40. The electrochemical sensor of claim 30, wherein an average molecular weight of the polymer is above about 1,000,000.

41. The electrochemical sensor of claim 30, wherein the polymer further comprises a B-containing copolymer such that the polymer has the formula:

42. The electrochemical sensor of claim 41, wherein B is selected from a group consisting of a chelator, a negatively charged constituent, a hydrophobic hydrocarbon consitituent, a hydrophilic hydroxyl or polyhydroxy constituent, a silicon polymer, and a poly(ethylene glycol).

43. The electrochemical sensor of claim 41, wherein B is a poly(ethylene glycol) having a molecular weight of from about 100 to about 20,000.

44. The electrochemical sensor of claim 41, wherein the polymer has a formula selected from a group consisting of:

45. The electrochemical sensor of claim 41, wherein [n/(n+m+l+p)]×

100% is from about 1% to about 25%.

46. The electrochemical sensor of claim 41, wherein [m/(n+m+l+p)]×

100% is from about 1% to about 15%.

47. The electrochemical sensor of claim 41, wherein [l/(n+m+l+p)]×

100% is from about 20% to about 90%.

48. The electrochemical sensor of claim 41, wherein [p/(n+m+l+p)]×

100% is from about 1% to about 50%.

49. The electrochemical sensor of claim 30 or 41, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of pyridine, imidazole, oxazole, thiazole, pyrazole, and any derivative thereof.

50. The electrochemical sensor of claim 30 or 41, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylimidazole, and 4-vinylimidazole.

51. The electrochemical sensor of claim 30 or 41, wherein the membrane is sufficient to limit a flux of glucose or lactate thereacross.

52. The electrochemical sensor of claim 30 or 41, wherein the membrane is sufficient to limit a flux of glucose or lactate thereacross in vivo.

53. The electrochemical sensor of claim 30 or 41, wherein the crosslinker comprises at least one epoxide reactive group.

54. The electrochemical sensor of claim 30 or 41, wherein the crosslinker has a molecular weight of from about 200 to about 2000.

55. The electrochemical sensor of claim 30 or 41, wherein the crosslinker is a derivative of poly(ethylene glycol) or poly(propylene glycol).

56. The electrochemical sensor of claim 30 or 41, wherein a weight ratio of the polymer to the crosslinker is from about 4:

1 to about 32;

1.

57. The electrochemical sensor of claim 30 or 41, wherein a weight ratio of the polymer to the crosslinker is from about 8:

1 to about 16;

1.

58. The electrochemical sensor of claim 30, wherein the membrane further comprises a layer of poly(ethylene glycol).

59. The electrochemical sensor of claim 30, wherein the sensing layer comprises an enzyme, an enzyme stabilizer, and a crosslinker.

60. The electrochemical sensor of claim 30, wherein the sensing layer comprises an enzyme, a polymeric mediator, and a crosslinker.

61. A membrane for use in an electrochemical sensor, comprising:

a crosslinker; and

a polymer having the formula;

wherein the solid horizontal line represents a polymer backbone;

A is strong acid; and

each of n, l, p and q is independently a positive number.

62. The membrane of claim 61, wherein A is such that the heterocyclic nitrogen to which it is attached is zwitterionic.

63. The membrane of claim 61, wherein A is a stronger acid than carboxylic acid.

64. The membrane of claim 61, wherein the polymer further comprises a B-containing copolymer such that the polymer has the formula:

65. The membrane of claim 61, wherein B is selected from a group consisting of a chelator, a negatively charged constituent, a hydrophobic hydrocarbon constituent, a hydrophilic hydroxyl or polyhydroxy constituent, a silicon polymer, and a poly(ethylene glycol).

66. The membrane of claim 61 or 64, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylimidazole, and 4-vinylimidazole.

67. The membrane of claim 61 or 64 sufficient to limit a flux of glucose or lactate thereacross.

68. The membrane of claim 61 or 64 sufficient to limit a flux of glucose or lactate thereacross in vivo.

69. The membrane of claim 61 or 64, wherein the crosslinker comprises at least one epoxide reactive group.

70. The membrane of claim 61 or 64, wherein the crosslinker has a molecular weight of from about 200 to about 2000.

71. The membrane of claim 61 or 64, wherein the crosslinker is a derivative of poly(ethylene glycol) or poly(propylene glycol).

72. The membrane of claim 61 or 64, wherein a weight ratio of the polymer to the crosslinker is from about 4:

1 to about 32;

1.

73. The membrane of claim 61 or 64, wherein a weight ratio of the polymer to the crosslinker is from about 8:

1 to about 16;

1.

74. An electrochemical sensor, comprising:

a working electrode comprising;

a sensing layer in contact with a conductive material of the electrode;

a membrane disposed over the sensing layer, the membrane comprising a crosslinker and a polymer having the formula;

wherein the solid horizontal line represents a polymer backbone;

A is strong acid; and

each of n, l, p and q is independently a positive number; and

a counter electrode in electrochemical communication with the working electrode.

75. The electrochemical sensor of claim 74, wherein A is such that the heterocyclic nitrogen to which it is attached is zwitterionic.

76. The electrochemical sensor of claim 74, wherein A is a stronger acid than carboxylic acid.

77. The electrochemical sensor of claim 74, wherein the polymer further comprises a B-containing copolymer such that the polymer has the formula:

78. The electrochemical sensor of claim 77, wherein B is selected from a group consisting of a chelator, a negatively charged constituent, a hydrophobic hydrocarbon constituent, a hydrophilic hydroxyl or polyhydroxy constituent, a silicon polymer, and a poly(ethylene glycol).

79. The electrochemical sensor of claim 74 or 77, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of pyridine, imidazole, oxazole, thiazole, pyrazole, and any derivative thereof.

80. The electrochemical sensor of claim 74 or 77, wherein at least one heterocyclic nitrogen constituent of the polymer is independently selected from a group consisting of 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylimidazole, and 4-vinylimidazole.

81. The electrochemical sensor of claim 74 or 77 sufficient to limit a flux of glucose or lactate thereacross.

82. The electrochemical sensor of claim 74 or 77 sufficient to limit a flux of glucose or lactose thereacross in vivo.

83. The electrochemical sensor of claim 74 or 77, wherein the crosslinker comprises at least one epoxide reactive group.

84. The electrochemical sensor of claim 74 or 77, wherein the crosslinker has a molecular weight of from about 200 to about 2000.

85. The electrochemical sensor of claim 74 or 77, wherein the crosslinker is a derivative of poly(ethylene glycol) or poly(propylene glycol).

86. The electrochemical sensor of claim 74 or 77, wherein a weight ratio of the polymer to the crosslinker is from about 4:

1 to about 32;

1.

87. The electrochemical sensor of claim 74 or 77, wherein a weight ratio of the polymer to the crosslinker is from about 8:

1 to about 16;

1.

88. The electrochemical sensor of claim 74, wherein the sensing layer comprises an enzyme, an enzyme stabilizer, and a crosslinker.

89. The electrochemical sensor of claim 74, wherein the sensing layer comprises an enzyme, a polymeric mediator, and a crosslinker.