Analyte sensors having temperature independent membranes
Embodiments of the present disclosure relate to analyte determining methods and devices (e.g., electrochemical analyte monitoring systems) that have a membrane structure with an analyte permeability that is substantially temperature independent. The devices also include a sensing layer disposed on a working electrode of in vivo analyte sensors, e.g., continuous and/or automatic in vivo monitoring using analyte sensors and/or test strips. Also provided are systems and methods of using the, for example electrochemical, analyte sensors in analyte monitoring.
1. An analyte sensor comprising:
a working electrode;
a counter electrode;
a sensing layer disposed on the working electrode; and
a stacked membrane structure disposed on the sensing layer, wherein the stacked membrane structure comprises:
a first membrane having a negative temperature coefficient; and
a second membrane having a positive temperature coefficient;
wherein the stacked membrane structure has an analyte permeability that is substantially temperature independent.
2. The analyte sensor of claim 1 , wherein the first membrane is disposed on the sensing layer and the second membrane is disposed on the first membrane.
3. The analyte sensor of claim 1 , wherein the second membrane is disposed on the sensing layer and the first membrane is disposed on the second membrane.
4. The analyte sensor of claim 1 , wherein the analyte sensor generates signals that are substantially temperature independent over a range of temperatures.
5. The analyte sensor of claim 4 , wherein the range of temperatures is from 25° C. to 45° C.
6. The analyte sensor of claim 4 , wherein the analyte sensor generates signals that are within 90% or more of each other over the temperature range at a constant analyte concentration.
7. The analyte sensor of claim 4 , wherein the analyte sensor generates signals that are within 95% or more of each other over the temperature range at a constant analyte concentration.
8. The analyte sensor of claim 1 , wherein the stacked membrane structure is configured to have a total temperature coefficient that is substantially zero.
9. The analyte sensor of claim 1 , wherein the first membrane is configured to have an analyte permeability that varies inversely with temperature, and the second membrane is configured to have an analyte permeability that varies directly with temperature.
10. The analyte sensor of claim 1 , wherein the first membrane comprises: poly(styrene-co-maleic anhydride), dodecylamine and poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (2-aminopropyl ether) crosslinked with poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether); poly(n-isopropyl acrylamide); or a copolymer of poly(ethylene oxide) and poly(propylene oxide).
11. The analyte sensor of claim 1 , wherein the second membrane comprises polyvinylpyridine, a derivative of polyvinylpyridine, polyvinylimidazole, a derivative of polyvinylimidazole, or a combination thereof.
12. The analyte sensor of claim 1 , wherein the first and second membranes are chemically bound to each other.
13. The analyte sensor of claim 1 , wherein the first and second membranes are laminated to each other.
14. The analyte sensor of claim 1 , wherein the first and second membranes are crosslinked to each other.
15. The analyte sensor of claim 1 , wherein the stacked membrane structure is chemically bound to the sensing layer.
16. The analyte sensor of claim 1 , wherein the stacked membrane structure is laminated to the sensing layer.
17. The analyte sensor of claim 1 , wherein the stacked membrane structure is crosslinked to the sensing layer.
18. The analyte sensor of claim 1 , wherein the stacked membrane structure is configured to be a diffusion-limiting membrane structure.
19. The analyte sensor of claim 1 , wherein the stacked membrane structure is configured to be a size-exclusion membrane structure.
20. The analyte sensor of claim 1 , wherein the sensing layer comprises an analyte-responsive enzyme and a redox mediator.
21. The analyte sensor of claim 20 , wherein at least one of the analyte-responsive enzyme and the redox mediator is chemically bound to a polymer.
22. The analyte sensor of claim 20 , wherein at least one of the analyte-responsive enzyme and the redox mediator is crosslinked to a polymer.
23. The analyte sensor of claim 20 , wherein the redox mediator comprises a ruthenium-containing complex or an osmium-containing complex.
24. The analyte sensor of claim 20 , wherein the analyte sensor is a glucose sensor.
25. The analyte sensor of claim 20 , wherein the analyte sensor is an in vivo sensor.
26. The analyte sensor of claim 20 , wherein at least a portion of the analyte sensor is adapted to be positioned under skin of a subject.
27. A method of monitoring a level of an analyte in a subject, the method comprising:
positioning at least a portion of an analyte sensor into skin of a subject, wherein the analyte sensor comprises:
a working electrode;
a counter electrode;
a sensing layer disposed on the working electrode; and
a stacked membrane structure disposed on the sensing layer, wherein the stacked membrane structure comprises:
a first membrane having a negative temperature coefficient; and
a second membrane having a positive temperature coefficient,
wherein the stacked membrane structure has an analyte permeability that is substantially temperature independent; and
determining a level of an analyte over a period of time from signals generated by the analyte sensor, wherein the determining over a period of time provides for monitoring the level of the analyte in the subject.
28. The method of claim 27 , wherein the first membrane is disposed on the sensing layer and the second membrane is disposed on the first membrane.
29. The method of claim 27 , wherein the second membrane is disposed on the sensing layer and the first membrane is disposed on the second membrane.
30. The method of claim 28 , wherein the determining the level of the analyte over a period of time provides for monitoring the level of the analyte in the subject in the absence of correcting for temperature variation at the sensor.
31. The method of claim 27 , wherein the signals generated by the analyte sensor are substantially temperature independent over a range of temperatures.
32. The method of claim 31 , wherein the range of temperatures is from 25° C. to 45° C.
33. The method of claim 31 , wherein signals generated by the analyte sensor are within 90% or more of each other over the temperature range at a constant analyte concentration.
34. The method of claim 31 , wherein the signals generated by the analyte sensor are within 95% or more of each other over the temperature range at a constant analyte concentration.
35. The method of claim 27 , wherein the stacked membrane structure is configured to have a total temperature coefficient that is substantially zero.
36. The method of claim 27 , wherein the first membrane is configured to have an analyte permeability that varies inversely with temperature, and the second membrane is configured to have an analyte permeability that varies directly with temperature.
37. The method of claim 27 , wherein the first membrane comprises: poly(styrene-co-maleic anhydride), dodecylamine and poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (2-aminopropyl ether) crosslinked with poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether); poly(n-isopropyl acrylamide); or a copolymer of poly(ethylene oxide) and poly(propylene oxide).
38. The method of claim 27 , wherein the second membrane comprises polyvinylpyridine, a derivative of polyvinylpyridine, polyvinylimidazole, a derivative of polyvinylimidazole, or a combination thereof.
39. The method of claim 27 , wherein the first and second membranes are chemically bound to each other.
40. The method of claim 27 , wherein the first and second membranes are laminated to each other.
41. The method of claim 27 , wherein the first and second membranes are crosslinked to each other.
42. The method of claim 27 , wherein the stacked membrane structure is chemically bound to the sensing layer.
43. The method of claim 27 , wherein the stacked membrane structure is laminated to the sensing layer.
44. The method of claim 27 , wherein the stacked membrane structure is crosslinked to the sensing layer.
45. The method of claim 27 , wherein the stacked membrane structure is configured to be a diffusion-limiting membrane structure.
46. The method of claim 27 , wherein the stacked membrane structure is configured to be a size-exclusion membrane structure.
47. The method of claim 27 , wherein the sensing layer comprises an analyte-responsive enzyme and a redox mediator.
48. The method of claim 47 , wherein at least one of the analyte-responsive enzyme and the redox mediator is chemically bound to a polymer.
49. The method of claim 47 , wherein at least one of the analyte-responsive enzyme and the redox mediator is crosslinked to a polymer.
50. The method of claim 47 , wherein the redox mediator comprises a ruthenium-containing complex or an osmium-containing complex.
51. The method of claim 47 , wherein the analyte sensor is a glucose sensor.