CATALYTIC NANOCARBON ELECTRODES FOR BIOSENSORS
Embodiments of the present invention provide a method for detecting a composition comprising (a) providing a first composition which reacts with an oxidase to generate a second composition; (b) providing nitrogen-doped nanocarbons; and (c) detecting the first composition with the nanocarbons. Devices and systems containing such nitrogen-doped nanocarbons are also provided.
1 . A method for detecting a composition, comprising:
providing a first composition that reacts with an oxidase to generate a second composition; and
detecting the first composition with nitrogen-doped nanocarbons.
2 . The method of claim 1 , wherein the first composition is detected with the nanocarbons by detecting the second composition.
3 . The method of claim 1 , wherein providing a first composition that reacts with an oxidase to generate a second composition comprises providing a first composition that reacts with an oxidase to generate hydrogen peroxide.
4 . The method of claim 1 , wherein the nanocarbons catalyze the decomposition of the second composition, and wherein the first composition is detected by monitoring the decomposition of the second composition.
5 . The method of claim 1 , wherein detecting the substrate includes determining the concentration of the substrate in solution.
6 . The method of claim 1 , wherein detecting the first composition with nitrogen-doped nanocarbons comprises detecting the first composition with nitrogen-doped carbon nanotubes (N—CNTs).
7 . The method of claim 1 , wherein providing a first composition comprises providing a first composition selected from the group consisting of pyruvate, lactate, glutamate, ascorbate and glucose.
8 . The method of claim 1 , wherein detecting the first composition with nitrogen-doped nanocarbons comprises detecting the first composition with nanocarbons disposed on a surface of a first electrode.
9 . The method of claim 8 , wherein detecting the first composition further comprises detecting the first composition with the first electrode, a counter electrode, and a reference electrode.
10 . The method of claim 8 , wherein detecting the first composition further comprises detecting the first composition with a glassy carbon electrode, an Au wire electrode, and a saturated Hg/Hg 2 SO 4 electrode.
11 . A device for sensing a substrate, comprising:
a first electrode for sensing a first composition that reacts with an oxidase to generate a second composition; and
a plurality of nitrogen-doped nanocarbons disposed on a surface of said first electrode.
12 . The device of claim 11 , wherein the nanocarbons catalyze the decomposition of the second composition, and wherein the first electrode senses the first composition by monitoring the decomposition of the second composition.
13 . The device of claim 11 , wherein the nanocarbons are nitrogen-doped carbon nanotubes (N—CNTs).
14 . The device of claim 11 , wherein the first electrode is a carbon electrode.
15 . The device of claim 14 , wherein the first electrode is a glassy carbon electrode.
16 . The device of claim 11 , wherein the nanocarbons are disposed in a matrix comprising an ion exchange polymer.
17 . The device of claim 16 , wherein the ion exchange polymer is a persulfonated ion exchange polymer.
18 . The device of claim 17 , wherein the ion exchange polymer is modified with tetrabutylammonium bromide.
19 . The device of claim 16 , wherein the matrix further comprises a portion of the oxidase.
20 . The device of claim 16 , wherein the matrix is a film in which the oxidase is co-immobilized with the nanocarbons.
21 . The device of claim 11 , wherein the nanocarbons are N—CNTs having average nominal lengths within the range of about 5 μm to about 15 μm.
22 . The device of claim 11 , wherein the nanocarbons are N—CNTs having average nominal diameters within the range of about 10 μm to about 50 μm.
23 . The device of claim 11 , wherein the device further comprises a counter electrode and a reference electrode.
24 . The device of claim 23 , wherein the counter electrode is an Au wire electrode, and wherein the reference electrode is a saturated Hg/HgSO 4 electrode.
25 . A substrate sensing system, comprising:
a first electrode for sensing a first composition that reacts with an oxidase to generate a second composition;
a plurality of nitrogen-doped nanocarbons disposed on a surface of said first electrode; and
at least one electrical component for processing a signal or current generated by the second composition and detected by the first electrode, wherein the signal or current detected is indicative of a concentration of the first composition.