POLYMER MEMBRANES FOR CONTINUOUS ANALYTE SENSORS

• US 20100096259A1
• Filed: 11/30/2009
• Published: 04/22/2010
• Est. Priority Date: 03/28/2008
• Status: Abandoned Application

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert, Zhang, Huashi
• Application Number:
  US12/628,095
• Publication Number:
  US 20100096259A1
• Time in Patent Office: Days
• US Class Current: 204/290.11
• 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 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

Devices and methods are described for providing continuous measurement of an analyte concentration. In some embodiments, the device has a sensing mechanism and a sensing membrane that includes at least one surface-active group-containing polymer and that is located over the sensing mechanism. The sensing membrane may have a bioprotective layer configured to substantially block the effect and/or influence of non-constant noise-causing species.

Claims

1. A method for manufacturing an electrode for measuring a concentration of an analyte, the method comprising:

preparing a colloidal dispersion of a blend of a hydrophobic polymer and a hydrophilic polymer in water;

dipping at least a portion of an elongated conductive body into the colloidal dispersion, wherein the elongated conductive body comprises at least one electroactive surface and a first domain comprising an enzyme configured to react with the analyte; and

removing water from the dipped portion to leave behind, on the elongated conductive body, a second domain configured to control a flux of the analyte therethrough, whereby an electrode for measuring a concentration of the analyte is obtained.

2. The method of claim 1, wherein the hydrophobic polymer is a polyurethane.

3. The method of claim 2, wherein the polyurethane is selected from the group consisting of polyether-urethane-urea, polycarbonate-urethane, polyether-urethane, silicone-polyether-urethane, silicone-polycarbonate-urethane, and polyester-urethane.

4. The method of claim 1, wherein the hydrophilic polymer is selected from the group consisting of polyvinyl acetate, poly(ethylene glycol), polyacrylamide, acetates, polyethylene oxide, poly ethyl acrylate, and polyvinylpyrrolidone.

5. The method of claim 1, further comprising performing crosslinking on the second domain.

6. The method of claim 5, wherein the crosslinking is performed by ultraviolet curing.

7. The method of claim 5, wherein the crosslinking is performed by using a crosslinking agent.

8. The method of claim 1, further comprising controlling a thickness of the second domain to from about 0.05 microns to about 100 microns.

9. The method of claim 1, wherein the blend comprises from about 5 wt. % to about 50 wt. % of the hydrophilic polymer.

10. The method of claim 1, wherein the hydrophilic polymer has a molecular weight of from about 25,000 daltons to about 5,000,000 daltons.

11. The method of claim 1, wherein the second domain has an oxygen-to-analyte permeability ratio greater than about 100 to 1.

12. The method of claim 1, wherein the second domain has an oxygen-to-analyte permeability ratio greater than about 200 to 1.

13. The method of claim 1, wherein the second domain has an oxygen-to-analyte permeability ratio greater than about 300 to 1.

14. The method of claim 1, wherein removing water comprises evaporating water.

15. The method of claim 1, wherein the analyte is glucose and the enzyme is glucose oxidase.

16. An electrode for measuring an analyte concentration, prepared by a process comprising:

preparing a colloidal dispersion of a blend of a hydrophobic polymer and a hydrophilic polymer in water;

dipping at least a portion of an elongated conductive body into the colloidal dispersion, wherein the elongated conductive body comprises at least one electroactive surface and a first domain comprising an enzyme configured to react with the analyte; and

removing water from the dipped portion to leave behind, on the elongated conductive body, a second domain configured to control a flux of the analyte therethrough.

17. The electrode of claim 16, wherein the hydrophobic polymer is a polyurethane.

18. The electrode of claim 16, wherein the hydrophilic polymer is selected from the group consisting of polyvinyl acetate, poly(ethylene glycol), polyacrylamide, acetates, polyethylene oxide, poly ethyl acrylate, and polyvinylpyrrolidone.

19. The electrode of claim 16, wherein the hydrophobic polymer and the hydrophilic polymer are crosslinked.

20. The electrode of claim 16, wherein removing water comprises evaporating water.

21. The electrode of claim 16, wherein the second domain has an oxygen-to-analyte permeability ratio greater than about 100 to 1.