Sensors including redox-active selector complexes
A sensor can include a redox-active complex. The sensor can be voltage sensitive.
1. A sensor comprising:
a conductive region in electrical communication with at least three electrodes,
the electrodes insulated and separated from each other with a dielectric layer having an adhesion layer thereon, the electrodes including source-drain electrodes, and
the conductive region including a conductive material and an in situ activated redox-active selector comprising a metalloporphyrin, the metalloporphyrin immobilized with respect to a carbon nanotube in the conductive material by a ligand that is covalently bound to the carbon nanotube, the redox-active selector responsive to an applied gate voltage that transiently reduces the redox-active selector such that the in situ activated redox-active selector is configured to bind an analyte more readily in a first redox state compared to a second redox state, the sensor having a selectivity to ppm levels of carbon monoxide in air and being operational in air.
2. The sensor of claim 1 , wherein the conductive material includes a carbon material.
3. The sensor of claim 2 , wherein the carbon material includes amorphous carbon, graphene, graphite, a single walled carbon nanotube, and/or a multiwalled carbon nanotube.
4. The sensor of claim 1 , wherein the conductive material includes a conductive polymer.
5. The sensor of claim 1 , wherein the analyte is carbon monoxide.
6. The sensor of claim 5 , wherein the metalloporphyrin is capable of forming a stable complex with the carbon monoxide.
7. The sensor of claim 1 , wherein the metalloporphyrin includes iron.
8. The sensor of claim 1 , wherein the ligand that is covalently bound to the carbon nanotube is bound to the metalloporphyrin.
9. The sensor of claim 1 , wherein the ligand that is covalently bound to the carbon nanotube is a nitrogen-containing ligand.
10. The sensor of claim 1 , wherein the ligand that is covalently bound to the carbon nanotube includes a pyridyl group.
11. The sensor of claim 1 , wherein the redox-active selector includes an iron porphyrin complex and/or a triphenylmethyl compound.
12. The sensor of claim 1 , wherein the three electrodes include a source electrode, a drain electrode and a gate electrode.
13. A method of sensing an analyte, comprising:
exposing a sensor to a sample, the sensor including:
a conductive region in electrical communication with at least three electrodes, the electrodes insulated and separated from each other with a dielectric layer having an adhesion layer thereon, the electrodes including source-drain electrodes,
the conductive region including a conductive material and an in situ activated redox-active selector comprising a metalloporphyrin, the metalloporphyrin immobilized with respect to a carbon nanotube in the conductive material by a ligand that is covalently bound to the carbon nanotube, the redox-active selector responsive to an applied gate voltage that transiently reduces the redox-active selector such that the in situ activated redox-active selector is configured to bind an analyte in the sample more readily in a first redox state compared to a second redox state, the sensor having a selectivity to ppm levels of carbon monoxide in air and being operational in air; and
measuring an electrical property at the electrodes.
14. The method of claim 13 , wherein the sample is a gas.
15. The method of claim 13 , wherein the conductive material includes a carbon material or a conducting polymer.
16. The method of claim 15 , wherein the carbon material includes amorphous carbon, graphene, graphite, a single walled carbon nanotube, and/or a multiwalled carbon nanotube.
17. The method of claim 13 , wherein the analyte is carbon monoxide or a sulfide.
18. The method of claim 17 , wherein the metalloporphyrin is capable of forming a stable complex with the carbon monoxide.
19. The method of claim 13 , further comprising applying a negative gate voltage.
20. A method of preparing a sensor comprising:
forming a conductive region in electrical communication with at least three electrodes, the electrodes insulated and separated from each other with a dielectric layer having an adhesion layer thereon, the electrodes including source-drain electrodes,
the conductive region including a conductive material and an in situ activated redox-active selector comprising a metalloporphyrin, the metalloporphyrin immobilized with respect to a carbon nanotube in the conductive material by a ligand that is covalently bound to the carbon nanotube, the redox-active selector responsive to an applied gate voltage that transiently reduces the redox-active selector such that the in situ activated redox-active selector is configured to bind an analyte more readily in a first redox state compared to a second redox state, the sensor having a selectivity to ppm levels of carbon monoxide in air and being operational in air.