Graphene-based gas and bio sensor with high sensitivity and selectivity
View Patent ↗A graphene sensor and method for selective sensing of vapors, gases and biological agents are disclosed. The graphene sensor can include a substrate; a dielectric substrate on an upper layer of the substrate; a layer of graphene on an upper layer of the dielectric substrate; and a source and drain contact on an upper surface of the layer of graphene. The method for detection of vapors, gases and biological objects with low frequency input as a sensing parameter can include exposing a graphene device to at least one vapor, gas, and/or biological object, the graphene device comprising: a substrate; a dielectric substrate on an upper layer of the substrate, a layer of graphene on an upper layer of the dielectric substrate, and a source and drain contact on an upper surface of the layer of graphene; and measuring a change in a noise spectra of the graphene device.
1. A graphene sensor for selective sensing of vapors, gases and biological agents, the graphene sensor comprising:
a substrate;
a dielectric substrate on an upper layer of the substrate;
a layer of graphene on an upper layer of the dielectric substrate;
a source and drain contact on an upper surface of the layer of graphene;
a pre-amplifier configured to amplify current fluctuations; and
a low-pass and/or a high-pass filter configured to pass the amplified current fluctuations for analyzation.
2. The graphene sensor of claim 1 , wherein the layer of graphene is single layer graphene (SLG).
3. The graphene sensor of claim 1 , wherein the layer of graphene is a bilayer graphene (BLG).
4. The graphene sensor of claim 1 , wherein the substrate is a p-typed highly-doped Si wafer.
5. The graphene sensor of claim 1 , wherein the dielectric substrate is 300-nm thermally grown SiO 2 .
6. The graphene sensor of claim 1 , wherein the source and drain contact are Cr/Au.
7. The graphene sensor of claim 1 , wherein the source and drain contact are Ti/Au.
8. The graphene sensor of claim 1 , comprising:
a pair of Cr/Au contact pads.
9. The graphene sensor of claim 1 , comprising:
a signal analyzer to measure a noise power spectrum.
10. The graphene sensor of claim 1 , comprising:
an electrical circuit for a low frequency noise spectrum input.
11. The graphene sensor of claim 1 , wherein the low-pass and/or the high-pass filter are configured to pass frequencies from 0.03 Hz to 100 KHz.
12. A graphene sensor for selective sensing of vapors, gases and biological agents, the graphene sensor comprising:
a substrate;
a dielectric substrate on an upper layer of the substrate;
one or more ribbons of graphene on an upper layer of the dielectric substrate;
a metal electrode acting as a source and drain contact;
a pre-amplifier configured to amplify current fluctuations; and
a low-pass and/or a high-pass filter configured to pass the amplified current fluctuations for analyzation.
13. The graphene sensor of claim 12 , wherein the one or more graphene ribbons comprise a plurality of graphene ribbons.
14. The graphene sensor of claim 13 , wherein each of the plurality of graphene ribbons has multiple electrodes.
15. The graphene sensor of claim 14 , wherein the multiple electrodes have different distances between a pair of electrodes.
16. The graphene sensor of claim 12 , comprising:
a signal analyzer to measure a noise power spectrum.
17. A method for selective detection of vapors, gases and biological objects with low frequency input as a sensing parameter using a graphene device, the method comprising:
exposing the graphene device to at least one vapor, gas, and/or biological object, the graphene device comprising a substrate, a dielectric substrate on an upper layer of the substrate, a layer of graphene on an upper layer of the dielectric substrate, and a source and drain contact on an upper surface of the layer of graphene, a pre-amplifier configured to amplify current fluctuations, and a low-pass and/or a high-pass filter configured to pass the amplified current fluctuations for analyzation; and
measuring a change in a noise spectra of the amplified current fluctuations of the graphene device.
18. The method of claim 17 , comprising:
measuring the change in the noise spectra of the graphene device with a signal analyzer.
19. A method for selective detection of vapors, gases and biological objects with low frequency input as a sensing parameter using a graphene device, the method comprising:
exposing the graphene device to at least one vapor, gas, and/or biological object, the graphene device comprising a substrate, a dielectric substrate on an upper layer of the substrate, one or more ribbons of graphene on an upper layer of the dielectric substrate, a metal electrode acting as a source and drain contact, a pre-amplifier configured to amplify current fluctuations, and a low-pass and/or a high-pass filter configured to pass the amplified current fluctuations for analyzation; and
measuring a change in a noise spectra of the amplified current fluctuations of the graphene device.
20. The method of claim 19 , comprising:
measuring the change in the noise spectra of the graphene device with a signal analyzer.