Working electrode of a continuous biological sensor
A working electrode for a subcutaneous sensor for use with a continuous biological monitor for a patient is disclosed. The working electrode includes a conductive substrate and a carbon-enzyme layer on the conductive substrate. The carbon-enzyme layer includes a polyurethane or silicone crosslinked with an acrylic polyol, and an enzyme fully entrapped by the polyurethane or silicone crosslinked with the acrylic polyol. The enzyme is selected according to a biological function to be monitored. The carbon-enzyme layer also includes a carbon material. The carbon-enzyme layer is electrically conductive and facilitates a generation of either peroxide or electrons within the carbon-enzyme layer responsive to reacting the enzyme with a target biologic from blood of the patient.
1. A working electrode for a subcutaneous sensor for use with a continuous biological monitor for a patient, comprising:
a conductive substrate; and
a carbon-enzyme layer on the conductive substrate, the carbon-enzyme layer comprising:
a polyurethane crosslinked with an acrylic polyol;
an enzyme fully entrapped by the polyurethane crosslinked with the acrylic polyol, the enzyme selected according to a biological function to be monitored; and
a carbon material;
wherein the carbon-enzyme layer is electrically conductive and facilitates a generation of either peroxide or electrons within the carbon-enzyme layer responsive to reacting the enzyme with a target biologic from blood of the patient.
2. The working electrode according to claim 1 , further including a glucose limiting layer over the carbon-enzyme layer that limits an amount of glucose from the blood of the patient that passes to the carbon-enzyme layer.
3. The working electrode according to claim 1 , wherein the enzyme is glucose oxidase (GOx), lactate dehydrogenase, lactate oxidase, or hydroxybutyrate dehydrogenase.
4. The working electrode according to claim 1 , wherein the enzyme is glucose oxidase (GOx) and the biological function is glucose level.
5. The working electrode according to claim 1 , wherein the polyurethane crosslinked with the acrylic polyol further comprises:
an additional cross-linker selected from imidoesters, hydroxysuccinimides, carbodilites, melamines, epoxies, benzoyl peroxides or dicumyl peroxides.
6. The working electrode according to claim 1 , wherein the carbon material comprises carbon, graphite, graphene, or pyrolytic graphite.
7. The working electrode according to claim 1 , further comprising a hydrophile selected from polyvinylpyrrolidone (PVP), polyethylene oxide (PEO) or silane-PEO (Si-PEO).
8. The working electrode according to claim 1 , wherein the carbon-enzyme layer has an approximate ratio of materials comprising:
0.5 to 2.0 parts of the polyurethane;
0.5 to 2.0 parts of the acrylic polyol;
0.01 to 0.1 parts of the enzyme; and
0.5 to 2.0 parts of the carbon material.
9. The working electrode according to claim 8 , wherein the carbon material further comprises:
0.5 to 1.0 parts of a graphite;
0.0 to 1.0 parts of a graphene; and
0.0 to 2.0 parts of a pyrolytic graphite.
10. The working electrode according to claim 8 , wherein the carbon-enzyme layer further comprises 0.0 to 3.0 parts of water and a hydrophile.
11. A working electrode for a subcutaneous sensor for use with a continuous biological monitor for a patient, comprising:
a conductive substrate; and
a carbon-enzyme layer on the conductive substrate, the carbon-enzyme layer comprising:
a silicone crosslinked with an acrylic polyol;
an enzyme fully entrapped by the silicone crosslinked with the acrylic polyol, the enzyme selected according to a biological function to be monitored; and
a carbon material;
wherein the carbon-enzyme layer is electrically conductive and facilitates a generation of either peroxide or electrons within the carbon-enzyme layer responsive to reacting the enzyme with a target biologic from blood of the patient.
12. The working electrode according to claim 11 , further including a glucose limiting layer over the carbon-enzyme layer that limits an amount of glucose from the blood of the patient that passes to the carbon-enzyme layer.
13. The working electrode according to claim 11 , wherein the enzyme is glucose oxidase (GOx), lactate dehydrogenase, lactate oxidase, or hydroxybutyrate dehydrogenase.
14. The working electrode according to claim 11 , wherein the enzyme is glucose oxidase (GOx) and the biological function is glucose level.
15. The working electrode according to claim 11 , wherein the silicone crosslinked with the acrylic polyol further comprises:
an additional cross-linker selected from imidoesters, hydroxysuccinimides, carbodilites, melamines, epoxies, benzoyl peroxides or dicumyl peroxides.
16. The working electrode according to claim 11 , wherein the carbon material comprises carbon, graphite, graphene, or pyrolytic graphite.
17. The working electrode according to claim 11 , further comprising a hydrophile selected from polyvinylpyrrolidone (PVP), polyethylene oxide (PEO) or silane-PEO (Si-PEO).
18. The working electrode according to claim 11 , wherein the carbon-enzyme layer has an approximate ratio of materials comprising:
0.5 to 2.0 parts of the silicone;
0.5 to 2.0 parts of the acrylic polyol;
0.01 to 0.1 parts of the enzyme; and
0.5 to 2.0 parts of the carbon material.
19. The working electrode according to claim 18 , wherein the carbon material further comprises:
0.5 to 1.0 parts of a graphite;
0.0 to 1.0 parts of a graphene; and
0.0 to 2.0 parts of a pyrolytic graphite.
20. The working electrode according to claim 18 , wherein the carbon-enzyme layer further comprises 0.0 to 3.0 parts of water and a hydrophile.