Dual electrode system for a continuous analyte sensor
Disclosed herein are systems and methods for a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes first and second working electrodes to measure analyte or non-analyte related signal, both of which electrode include an interference domain.
1. An analyte sensor configured for measuring an analyte in a host, the sensor comprising:
a first working electrode disposed beneath an active enzymatic portion of a sensor membrane, wherein the sensor membrane comprises a first interference domain located over the first working electrode, and wherein the first interference domain is configured to substantially block flow of at least one interfering species; and
a second working electrode disposed beneath an inactive-enzymatic portion of a sensor membrane or a non-enzymatic portion of a sensor membrane, wherein the sensor membrane comprises a second interference domain located over the second working electrode, wherein the second interference domain is configured to substantially block flow of at least one interfering species, and wherein the first interference domain is distinct from the second interference domain.
2. The analyte sensor of claim 1 , wherein the interference domain is configured to substantially block at least one interferent selected from the group consisting of acetaminophen, ascorbic acid, bilirubin, cholesterol, creatinine, dopamine, ephedrine, ibuprofen, L-dopa, methyldopa, salicylate, tetracycline, tolazamide, tolbutamide, triglycerides, and uric acid.
3. The analyte sensor of claim 1 , wherein the interference domain is configured to substantially block at least one interferent selected from the group consisting of hydrogen peroxide, reactive oxygen species, and reactive nitrogen species.
4. The analyte sensor of claim 1 , wherein the interference domain is configured to substantially block at least one non-constant noise causing interferent.
5. The analyte sensor of claim 1 , wherein the sensor membrane further comprises a blend of at least one hydrophilic component and at least one hydrophobic component, wherein the interference domain is configured such that the sensor provides an equivalent analyte signal response to at least one interferent that does not substantially affect accuracy of an in vivo analyte concentration measurement, and wherein the sensor is configured to provide a linear response to analyte concentration, in vivo, within in a physiological range.
6. The analyte sensor of claim 5 , wherein the hydrophilic component and the hydrophobic component each comprise at least one cellulosic derivative.
7. The analyte sensor of claim 1 , wherein the sensor membrane further comprises a silicone material configured to allow transport of an analyte therethrough.
8. The analyte sensor of claim 7 , wherein the silicone material comprises a blend of a silicone elastomer and a hydrophilic copolymer.
9. The analyte sensor of claim 1 , wherein the sensor membrane further comprises a polyurethane.
10. The analyte sensor of claim 1 , wherein the sensor membrane further comprises a polymer having pendant ionic groups.
11. The analyte sensor of claim 1 , wherein the sensor membrane further comprises a polymer membrane having a predetermined pore size that restricts diffusion of high molecular weight species.
12. The analyte sensor of claim 11 , wherein the high molecular weight species comprise at least one of glucose and ascorbic acid.
13. The analyte sensor of claim 1 , wherein the sensor is configured to be subcutaneously implanted.
14. The analyte sensor of claim 1 , wherein the sensor is configured to be intravascularly implanted.
15. The analyte sensor of claim 1 , wherein the sensor comprises an architecture with at least one dimension less than about 1 mm.
16. The analyte sensor of claim 1 , wherein the first interference domain and second interference domain are individually formed on each of the first electrode and the second electrode.
17. The analyte sensor of claim 1 , wherein the sensor comprises a diffusion barrier between the first electrode and the second electrode.
18. The analyte sensor of claim 1 , wherein the sensor comprises a diffusion barrier between the first interference domain and the second interference domain.
19. The analyte sensor of claim 1 , wherein the first and second interference domains are each configured to substantially block passage therethrough of at least one interferent such that an equivalent glucose signal response of the interferent is less than about 60 mg/dl.
20. The analyte sensor of claim 1 , wherein the interference domain is configured to substantially block at least one interferent selected from the group consisting of ureate, ascorbate, and acetaminophen.
21. The analyte sensor of claim 1 , wherein the interference domain is configured to substantially block at least one interferent having an oxidation potential that overlaps with the analyte to be measured.