Analyte sensors having nanostructured electrodes and methods for making and using them

• US 9,309,550 B2
• Filed: 01/28/2009
• Issued: 04/12/2016
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Cooper, Kenneth W., Vejella, Ratnakar, Soundararajan, Gopikrishnan, Shah, Rajiv
• Primary Examiner(s): BROWN, MELANIE YU
• Application Number:
  US12/361,413
• Publication Number:
  US 20090198117A1
• Time in Patent Office: 2,631 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C12Q 1/001 Enzyme electrodes

Abstract

Embodiments of the invention provide analyte sensors having nanostructured electrodes as well as methods for making and using such sensors. In certain embodiments of the invention, the sensor includes a carbon nanotube electrode and a analyte limiting membrane that modulates the ability of a analyte to contact the carbon nanotube electrode.

Claims

1. A method of sensing glucose within the body of a mammal, the method comprising implanting a glucose sensor into a mammal, wherein the glucose sensor comprises:

a base layer;

a conductive layer disposed upon the base layer wherein the conductive layer includes a working electrode comprising a plurality of conductive nanotubes;

an analyte sensing layer comprising glucose oxidase disposed on the conductive nanotubes, wherein the glucose oxidase generates hydrogen peroxide in the presence of glucose; and

an analyte modulating layer disposed on the analyte sensing layer, wherein the analyte modulating layer;

modulates the diffusion of glucose therethrough; and

includes a composition of matter comprising a hydrophilic comb-copolymer having a central chain and a plurality of side chains coupled to the central chain, wherein at least one side chain comprises a silicone moiety; and

sensing an alteration in electrical potential at the working electrode that results from hydrogen peroxide produced by the glucose oxidase in the presence of glucose;

and correlating the alteration in electrical potential with the presence of glucose, so that glucose is sensed.

2. The method of claim 1, wherein the method comprises sensing an alteration in electrical potential at a plurality of operating potentials.

3. The method of claim 1, wherein the analyte modulating layer has a glucose diffusion coefficient (D_glucose) of from 1×

10<sup>−

9</sup> cm²/sec to 200×

10<sup>−

9</sup> cm²/sec.

4. The method of claim 1, wherein the analyte modulating layer has a oxygen diffusion coefficient (D_oxygen) to glucose diffusion coefficient (D_glucose) ratio (D_oxygen/D_glucose) of from 5 to 2000.