Analyte sensor electrode arrangements

Patent metadata

Field	Value
Publication number	US-11638543-B2
Application number	US-202016929906-A
Country	US
Kind code	B2
Filing date	Jul 15, 2020
Priority date	Jul 16, 2019
Publication date	May 2, 2023
Grant date	May 2, 2023

Abstract

Various examples are directed to a glucose sensor comprising a working electrode to support an oxidation reaction and a reference electrode to support a redox reaction. The reference electrode may comprise silver and silver chloride. The Glucose sensor may also comprise an anti-mineralization agent positioned at the reference electrode to reduce formation of calcium carbonate at the reference electrode.

First claim

What is claimed is:

1. A glucose sensor comprising:
a working electrode to support an oxidation reaction; and
a reference electrode to support a redox reaction, the reference electrode comprising:
silver and silver chloride, wherein the silver comprises microscale silver particles having an average width of between about 1 micron and about 10 microns, and nanoscale silver particles having an average size that is less than 100 nanometers, wherein the nanoscale silver particles make up between about 0.1% and about 10% of the silver by volume; and
an anti-mineralization agent positioned at the reference electrode to reduce formation of calcium carbonate at the reference electrode.

2. The glucose sensor of claim 1 , wherein the reference electrode further comprises a mediator material to catalyze oxygen redox at the reference electrode at least in part with the silver.

3. The glucose sensor of claim 1 , wherein the anti-mineralization agent is selected from the group consisting of a polyacrylate and a carboxylate-containing polymer.

4. The glucose sensor of claim 1 , further comprising a membrane system comprising an anti-mineralization layer positioned at least in part over the reference electrode, the anti-mineralization layer comprising at least a portion of the anti-mineralization agent.

5. The glucose sensor of claim 4 , wherein the membrane system further comprises an interference domain positioned at least in part over the working electrode, the interference domain comprising a first interference agent and at least a portion of the anti-mineralization agent.

6. The glucose sensor of claim 1 , wherein the reference electrode comprises a binder material, and wherein the silver, the silver chloride, and the anti-mineralization agent are positioned within the binder material.

7. The glucose sensor of claim 1 , wherein the anti-mineralization agent comprises a polyacrylate.

8. The glucose sensor of claim 1 , wherein the anti-mineralization agent comprises a carboxylate-containing polymer.

9. The glucose sensor of claim 8 , wherein the carboxylate-containing polymer is selected from the group consisting of a poly(maleate), a polysulfonate, and a polyphosphonate.

10. The glucose sensor of claim 1 , further comprising a membrane system, the membrane system comprising:
a resistance domain positioned at least in part over the reference electrode; and
a hydrophilic domain positioned at least in part over the reference electrode.

11. The glucose sensor of claim 1 , wherein the silver chloride comprises particles of silver chloride having a diameter of between 0.5 microns and 5 microns.

12. A method of manufacturing a glucose sensor, comprising:
dipping a distal end of the glucose sensor into a first solution to a first depth from a distal end, the glucose sensor comprising a working electrode and a reference electrode comprising silver and silver chloride, wherein the silver comprises microscale silver particles having an average width of between about 1 micron and about 10 microns, and nanoscale silver particles having an average size that is less than 100 nanometers, wherein the nanoscale silver particles make up between about 0.1% and about 10% of the silver by volume, and wherein the first solution comprises a first agent, wherein, at the first depth, the first solution is positioned to cover the working electrode; and
dipping the distal end of the glucose sensor into a second solution to a second depth from the distal end, the second solution comprising an anti-mineralization agent, wherein, at the second depth, the second solution is positioned to cover the working electrode and to cover at least a portion of the reference electrode, wherein the first agent and an anti-mineralization agent form an interference domain over the working electrode.

13. The method of claim 12 , wherein the dipping of the distal end of the glucose sensor into the second solution is after the dipping of the distal end of the glucose sensor into the first solution, further comprising, after dipping the distal end of the glucose sensor into the second solution, re-dipping the distal end of the glucose sensor into the first solution to the first depth.

14. The method of claim 12 , wherein the dipping of the distal end the glucose sensor into the first solution is after the dipping of the distal end of the glucose sensor into the second solution, further comprising, after dipping the distal end of the glucose sensor into the first solution, re-dipping the distal end of the glucose sensor into the second solution to the second depth.

15. The method of claim 12 , further comprising dipping the distal end of the glucose sensor into a third solution comprising glucose oxidase.

16. The method of claim 12 , wherein the anti-mineralization agent comprises a polyacrylate.

17. The method of claim 12 , wherein the anti-mineralization agent comprises a carboxylate-containing polymer.

18. The method of claim 17 , wherein the carboxylate-containing polymer is selected from the group consisting of a poly(maleate), a polysulfonate, a polyphosphonate.

19. The method of claim 12 , further comprising:
applying a first current between the working electrode and the reference electrode; and
after applying the first current, generating a sensor current with the glucose sensor, a magnitude of the sensor current indicating glucose concentration at the glucose sensor, the first current being larger than the sensor current.

20. The method of claim 12 , further comprising:
immersing at least the reference electrode in a solution of chlorine bleach; and
after the immersing, generating a sensor current with the glucose sensor, a magnitude of the sensor current indicating glucose concentration at the glucose sensor.

Assignees

• Dexcom Inc

Inventors

• Bohm Sebastian
• Lan Wenjie
• Porter Thomas Robert
• Rong Daiting
• Halac Jason

Classifications

• G01N27/301

  Reference electrodes · CPC title

• G01N27/3271

  Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood (amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001) · CPC title

• C08G65/4056

  (I) or (II) containing sulfur (as the sulfone group C08G75/23) · CPC title

• A61B2562/125

  characterised by the manufacture of electrodes · CPC title

• A61B5/14532 Primary

  for measuring glucose, e.g. by tissue impedance measurement · CPC title