Analyte sensors having a signal-to-noise ratio substantially unaffected by non-constant noise

1. A diffusion-based glucose sensor, comprising:

an electrode configured to detect a signal related to a glucose concentration of a host; and

a membrane comprising a silicone-hydrophilic polymer blend configured to decrease diffusion of at least one interferent to the electrode, whereby a signal component related to the at least one interferent is less than 20% of the signal for at least one day in vivo, wherein the silicone-hydrophilic polymer blend is configured to slow diffusion of reactive oxygen and nitrogen interferents therethrough.

2. The sensor of claim 1 , wherein the silicone-hydrophilic polymer blend comprises a substantial blend of a silicone-containing polymer and a hydrophilic-hydrophobic polymer.

3. The sensor of claim 2 , wherein the hydrophilic-hydrophobic polymer is a PEO and PPO copolymer.

4. The sensor of claim 1 , wherein the silicone-hydrophilic polymer blend is configured to promote movement of water into the membrane.

5. The sensor of claim 1 , wherein the hydrophilic-hydrophobic polymer comprises hydrophilic and hydrophobic substituents.

6. The sensor of claim 1 , wherein the silicone-hydrophilic polymer blend is configured to sterically block diffusion of at least one interferent.

7. The glucose sensor of claim 1 , wherein the membrane comprises a tortuous pathway.

8. The glucose sensor of claim 1 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

9. The glucose sensor of claim 1 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

10. The glucose sensor of claim 1 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

11. The glucose sensor of claim 1 , wherein the membrane comprises a Heme compound.

12. The glucose sensor of claim 1 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

13. The glucose sensor of claim 1 , wherein the silicone-containing polymer is a polycarbosiloxane.

14. A diffusion-based analyte sensor configured for implantation in a host, the sensor comprising:

an electrode configured to measure a signal related to an analyte concentration of the host, wherein the signal comprises an analyte-related signal component and a non-analyte related signal component, wherein the non-analyte related signal component is related to a concentration of at least one noise-causing electroactive species, wherein the at least one noise-causing electroactive species comprises at least one species selected from the group consisting of reactive oxygen species, nitrogen species, and hydrogen peroxide formed in a metabolic process of the host; and

a membrane disposed over the electrode and configured to increase the analyte-related signal component relative to the non-analyte-related signal component, such that the non-analyte-related signal component does not substantially contribute to the signal over a time period of at least one day in vivo, wherein the membrane comprises:

a first domain comprising a blend of a silicone-containing polymer and a hydrophilic polymer;

a second domain comprising an enzyme; and

a third domain configured to reduce passage of interferents;

wherein the sensor has a sensitivity to analyte of from about 50 pA/mg/dL to about 500 pA/mg/dL.

15. The analyte sensor of claim 14 , wherein the noise-causing electroactive species comprises an electroactive species having a redox potential that substantially overlaps with a redox potential of a measured species indicative of the concentration of the analyte.

16. The analyte sensor of claim 15 , wherein the measured species comprises hydrogen peroxide.

17. The analyte sensor of claim 14 , wherein the membrane comprises a tortuous pathway.

18. The analyte sensor of claim 14 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

19. The analyte sensor of claim 14 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

20. The analyte sensor of claim 14 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

21. The analyte sensor of claim 14 , wherein the membrane comprises a Heme compound.

22. The analyte sensor of claim 14 , wherein the first domain is configured to restrict flow of the analyte therethrough.

23. The analyte sensor of claim 14 , wherein a signal contribution due to the non-analyte-related component is less than about 20% of the signal over a time period of at least about one day.

24. The analyte sensor of claim 14 , wherein a signal contribution due to the non-analyte-related component is less than about 10% of the signal over a time period of about one day.

25. The analyte sensor of claim 14 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

26. The analyte sensor of claim 14 , wherein the silicone-containing polymer is a polycarbosiloxane.

27. A diffusion-based analyte sensor configured for implantation in a host, the sensor comprising:

an electrode configured to measure a signal related to an analyte concentration of the host; and

a membrane disposed over the electrode, the membrane comprising:

a first domain comprising a blend of a silicone-containing polymer and a hydrophilic polymer that comprises polyvinylpyrrolidone;

a second domain comprising an enzyme and a hydrophilic polymer that comprises polyvinylpyrrolidone; and

a third domain configured to reduce passage of interferents;

wherein the sensor has a sensitivity to analyte of from about 50 A/mg/dL to about 500 pA/mg/dL.

28. The analyte sensor of claim 27 , wherein the membrane comprises a tortuous pathway.

29. The analyte sensor of claim 27 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

30. The analyte sensor of claim 27 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

31. The analyte sensor of claim 27 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

32. The analyte sensor of claim 27 , wherein the membrane comprises a Heme compound.

33. The analyte sensor of claim 27 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

34. The analyte sensor of claim 27 , wherein the silicone-containing polymer is a polycarbosiloxane.

35. A diffusion-based analyte sensor configured for implantation in a host, the sensor comprising:

an electrode configured to measure a signal related to an analyte concentration of the host, wherein the signal comprises an analyte-related signal component and a non-analyte related signal component, wherein the non-analyte related signal component is related to a concentration of at least one noise-causing electroactive species; and

a membrane disposed over the electrode, wherein the membrane is configured to consume at least one noise-causing electroactive species formed in a metabolic process of the host, wherein the membrane comprises:

a first domain comprising a blend of a silicone-containing polymer and a hydrophilic polymer;

a second domain comprising an enzyme; and

a third domain configured to reduce passage of interferents;

wherein the sensor has a sensitivity to analyte of from about 50 pA/mg/dL to about 500 pA/mg/dL.

36. The analyte sensor of claim 35 , wherein the silicone-containing polymer and the hydrophilic polymer of the first domain are cross-linked.

37. The analyte sensor of claim 35 , wherein the first domain is configured to reduce a flux of an interfering species.

38. The analyte sensor of claim 35 , wherein the second domain comprises a hydrophilic polymer.

39. The analyte sensor of claim 35 , wherein the third domain comprises ionic components.

40. The analyte sensor of claim 35 , wherein the sensor has a current density of from about 3×10 3 pA/mg/dL/cm 2 to about 6×10 6 pA/mg/dL/cm 2 .

41. The analyte sensor of claim 35 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

42. The analyte sensor of claim 35 , wherein the noise-causing electroactive species comprises an electroactive species having a redox potential that substantially overlaps with a redox potential of a measured species indicative of the concentration of the analyte.

43. The analyte sensor of claim 42 , wherein the measured species comprises hydrogen peroxide.

44. The analyte sensor of claim 35 , wherein the membrane comprises a tortuous pathway.

45. The analyte sensor of claim 35 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

46. The analyte sensor of claim 35 , wherein the silicone-containing polymer is a polycarbosiloxane.

47. The analyte sensor of claim 35 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

48. The analyte sensor of claim 35 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

49. The analyte sensor of claim 35 , wherein the membrane comprises a Heme compound.

50. The analyte sensor of claim 35 , wherein the first domain is configured to restrict flow of the analyte therethrough.

51. The analyte sensor of claim 35 , wherein the membrane is configured to increase the analyte-related signal component relative to the non-analyte-related signal component, such that the non-analyte-related signal component does not substantially contribute to the signal over a time period of at least one day in vivo.

52. The analyte sensor of claim 51 , wherein a signal contribution due to the non-analyte-related component is less than about 20% of the signal over a time period of at least about one day.

53. The analyte sensor of claim 51 , wherein a signal contribution due to the non-analyte-related component is less than about 10% of the signal over a time period of at least about one day.

54. An implantable analyte-detecting device, comprising:

an electrode configured to measure a signal related to an analyte concentration of the host, wherein the signal comprises an analyte-related signal component and a non-analyte-related signal component; and

a membrane disposed over the electrode and comprising a substantial blend of a silicone-containing polymer and a hydrophilic polymer, wherein at least about 75% of the silicone-containing polymer is not covalently linked to the hydrophilic polymer, and wherein the membrane is configured to increase the analye-related signal component relative to the non-analyte-related signal component, such that the non-analyte-related signal component does not substantially contribute to the signal over a time period of at least one day in vivo.

55. The device of claim 54 , wherein the membrane comprises a tortuous pathway.

56. The device of claim 54 , wherein the substantial blend comprises a cross-linker.

57. The device of claim 54 , wherein a signal contribution due to the non-analyte-related component is less than about 20% of the signal over a time period of at least about one day.

58. The device of claim 54 , wherein the non-analyte-related signal component is related to the concentration of at least one noise-causing electroactive species.

59. The device of claim 54 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

60. The device of claim 54 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

61. The device of claim 54 , wherein the biointerface membrane is configured to provide a thermodynamic barrier to analyte transport therethrough, such that the device can detect the analyte with a sensitivity of from about 1 pA/mg/dL to about 500 pA/mg/dL.

62. The device of claim 54 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

63. The device of claim 54 , wherein the membrane comprises a Heme compound.

64. The device of claim 54 , wherein the first domain is configured to restrict flow of the analyte therethrough.

65. The device of claim 54 , wherein a signal contribution due to the non-analyte-related component is less than about 10% of the signal over a time period of about one day.

66. The device of claim 54 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

67. The device of claim 54 , wherein the silicone-containing polymer is a polycarbosiloxane.

68. An implantable analyte-detecting device, comprising:

an electrode configured to measure a signal related to an analyte concentration of the host, wherein the signal comprises an analyte-related signal component and a non-analyte-related signal component; and

a membrane disposed over the electrode and comprising a substantial blend of a silicone-containing polymer and a hydrophilic polymer,wherein the membrane is configured to consume at least one noise-causing electroactive species formed in a metabolic process of the host, and wherein the membrane is configured to increase the analyte-related signal component relative to the non-analyte-related signal component, such that the non-analyte-related signal component does not substantially contribute to the signal over a time period of at least one day in vivo.

69. The device of claim 68 , wherein the at least one noise-causing electroactive species comprises at least one species selected from the group consisting of reactive oxygen species, nitrogen species, and hydrogen peroxide formed in a metabolic process of the host.

70. The device of claim 69 , wherein the noise-causing electroactive species comprises an electroactive species having a redox potential that substantially overlaps with a redox potential of a measured species indicative of the concentration of the analyte.

71. The device of claim 70 , wherein the measured species comprises hydrogen peroxide.

72. The device of claim 68 , wherein the membrane comprises a tortuous pathway.

73. The device of claim 68 , wherein the membrane is configured to sterically block at least one of acetaminophen or ascorbate.

74. The device of claim 68 , wherein a tissue-contacting surface of the membrane is discontinuously hydrophilic.

75. The device of claim 68 , wherein at least a portion of the membrane comprises a tortuous diffusion path configured to render inactive, at the electrode, at least one noise-causing electroactive species.

76. The device of claim 68 , wherein the membrane comprises a Heme compound.

77. The device of claim 68 , wherein a signal contribution due to the non-analyte-related component is less than about 20% of the signal over a time period of at least about one day.

78. The device of claim 68 , wherein a signal contribution due to the non-analyte-related component is less than about 10% of the signal over a time period of about one day.

79. The device of claim 68 , wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment.

80. The device of claim 68 , wherein the silicone-containing polymer is a polycarbosiloxane.

81. An implantable analyte-detecting device, comprising:

an electrode configured to measure a signal related to analyte concentration of the host, wherein the signal comprises an analyte-related signal component and a non-analyte-related signal component; and

a membrane disposed over the electrode and comprising a substantial blend of a silicone-containing polymer and a hydrophilic polymer, wherein the substantial blend of a silicone-containing polymer and a hydrophilic polymer is configured to form micellar jackets, and wherein the membrane is configured to increase the analyte-related signal component relative to the non-analyte-related signal component, such that the non-analyte-related signal component does not substantially contribute to the signal over a time period of at least one day in vivo.

82. The device of claim 81 , wherein the micellar jackets are configured to provide a contiguous hydrophilic path for analyte transport through the biointerface membrane.

83. A diffusion-based glucose sensor, comprising:

an electrode configured to detect a signal related to a glucose concentration of a host; and

a membrane comprising a silicone-hydrophilic polymer blend configured to decrease diffusion of at least one interferent to the electrode, whereby a signal component related to the at least one interferent is less than 20% of the signal for at least one day in vivo, wherein the silicone-hydrophilic polymer blend is configured for the self-organization of micellar jackets around colloidal silicone globules.