Analyte sensors having nanostructured electrodes and methods for making and using them
View Patent ↗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.
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 −9 cm 2 /sec to 200×10 −9 cm 2 /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.