Electrodes with multilayer membranes and methods of using and making the electrodes

• US 20010054319A1
• Filed: 05/11/2001
• Published: 12/27/2001
• Est. Priority Date: 05/12/2000
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Original Assignee: Therasense Incorporated (Abbott Laboratories)
• Inventors: Heller, Adam, Friedman, Keith A., Chen, Ting
• Granted Patent: US 6,746,582 B2
• Time in Patent Office: Days
• US Class Current: 73/849
• CPC Class Codes: G01N 27/3271 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

Abstract

A sensor including a sensing layer is disposed over an electrode or an optode and a layer-by-layer assembled mass transport limiting membrane disposed over the sensing layer. The membrane includes at least one layer of a polyanionic or polycationic material. The assembled layers of the membrane are typically disposed in an alternating manner. The sensor also optionally includes a biocompatible membrane.

Claims

1. A sensor, comprising:

a sensing layer disposed on a substrate;

a multilayer flux-limiting membrane disposed over the sensing layer, the membrane comprising a first layer disposed on the sensing layer, the first layer binding to the sensing layer, the membrane further comprising one or more subsequent layers disposed on and bound to the immediately preceding layer of the membrane.

2. The sensor of

claim 1

, wherein the sensor has an active area of 0.1 cm² or less.

3. The sensor of

claim 1

, wherein the active area is in a range of 10⁻

2 cm² to 10<sup>−

8</sup> cm².

4. The sensor of

claim 1

, wherein the active area is in a range of 10⁻

3 cm² to 10<sup>−

6</sup> cm².

5. The sensor of

claim 1

, wherein the sensing layer comprises an enzyme.

6. The sensor of

claim 1

, wherein the substrate comprises an electrode upon which the sensing layer is disposed.

7. The sensor of

claim 1

, wherein the substrate comprises an optical fiber upon which the sensing layer is disposed.

8. The sensor of

claim 7

, wherein the sensing layer is disposed on a tip of the optical fiber.

9. The sensor of

claim 1

, wherein the sensing layer comprises a non-leachable redox compound.

10. The sensor of

claim 9

, wherein the non-leachable redox compound comprises a redox polymer.

11. The sensor of

claim 1

, wherein the multilayer membrane comprises at least one polycationic layer.

12. The sensor of

claim 1

, wherein the multilayer membrane comprises at least one polyanionic layer.

13. The sensor of

claim 1

, wherein the multilayer membrane comprises at least one polycationic layer and at least one polyanionic layer.

14. The sensor of

claim 1

, wherein the sensor is adapted for implantation of at least a portion of the sensor in an animal.

15. The sensor of

claim 1

, wherein the sensor is adapted for subcutaneous implantation of at least a portion of the sensor in an animal.

16. The sensor of

claim 1

, further comprising a biocompatible layer disposed over the multilayer membrane.

17. The sensor of

claim 1

, wherein the membrane comprises at least two layers alternating between polyanionic material and polycationic material.

18. The sensor of

claim 1

, wherein at least one of the layers of the multilayer membrane comprises functional groups that can capture transition metal ions.

19. The sensor of

claim 1

, wherein the membrane is configured and arranged to reduce flux of an analyte to the sensing layer.

20. The sensor of

claim 1

, wherein the membrane is configured and arranged to reduce flux of at least one interferent to the sensing layer.

21. The sensor of

claim 1

, wherein the multilayer membrane comprises at least three layers.

22. The sensor of

claim 1

, wherein the multilayer membrane comprises at least six layers.

23. A method of making a sensor, the method comprising steps of:

disposing a sensing layer on a surface; and

forming a membrane over the sensing layer by forming, in an alternating and binding manner, at least three layers, of which one is a polyanionic layer and two are polycationic layers or of which two are polyanionic layers and one is a polycationic layer.

24. The method of

claim 23

, further comprising disposing a biocompatible layer over the membrane.

25. A method of making a sensor, the method comprising steps of:

disposing a sensing layer on a substrate;

disposing a first membrane layer on the sensing layer and binding the first membrane layer to the sensing layer; and

disposing one or more subsequent membrane layers over the first membrane layer, each subsequent membrane layer binding to the preceding membrane layer.

26. The method of

claim 25

, wherein the membrane layers are bound to the sensing layer or preceding membrane layer by chemisorption or reactive adsorption.

27. The method of

claim 26

, further comprising rinsing after disposing at least one of the first membrane layer or the one or more subsequent membrane layers.