Optical COVID-19 detection system

1 . A device, comprising:

a substrate coupled to a metal oxide layer;

a graphene layer coupled to the metal oxide layer;

a chemical or biochemical linker functionalized with the graphene layer;

a plurality of SARS-COV-2 receptors that are bound to the graphene layer via the chemical or biochemical linker, wherein the plurality of SARS-COV-2 receptors comprise SARS-COV-2 spike antibodies or SARS-COV-2 spike proteins, wherein binding of target molecules to the plurality of SARS-COV-2 receptors changes a phononic energy of the graphene layer from a first phononic energy to a second phononic energy; and

a housing coupled to the substrate, wherein the housing provides unobstructed optical access to a target location on the graphene layer for Raman spectroscopy measurements, and wherein the housing comprises alignment features that enable repeatable positioning of the device relative to a Raman spectrometer for alignment of a laser with the target location on the graphene layer, wherein the optical access permits determination of the first phononic energy from the target location and the second phononic energy from the target location via Raman spectroscopy.

2 . The device of claim 1 , wherein the metal oxide layer comprises indium tin oxide (“ITO”) or Si/SiO 2 .

3 . The device of claim 1 , wherein the metal oxide layer is indium tin oxide, wherein the graphene layer is n-doped, when the plurality of SARS-COV-2 receptors are unattached to the target molecules.

4 . The device of claim 3 , wherein the graphene layer is configured to be p-doped, when the plurality of SARS-COV-2 receptors are attached to the target molecules.

5 . The device of claim 1 , wherein the chemical or biochemical linker comprises a plurality of metal atoms functionalized with the graphene layer with an eta-6, eta-5, eta-4, eta-3, eta-2, or eta 1 chemistry such that the plurality of metal atoms each bind at a first end to the graphene layer and at a second end with one of the plurality of SARS-COV-2 spike antibodies or spike proteins.

6 . The device of claim 1 , wherein the chemical or biochemical linker is a 1-Pyrenebutyric acid N-hydroxysuccinimide ester (PBASE) linker.

7 . The device of claim 1 , wherein the graphene layer is a monolayer.

8 . The device of claim 1 , wherein the plurality of SARS-COV-2 spike antibodies comprises a first-type of SARS-COV-2 spike antibodies having an affinity for a first-type of SARS-COV-2 spike protein for a first-type of SARS-COV-2 variant and a second-type of SARS-CoV-2 spike antibodies having an affinity for a second-type of SARS-COV-2 spike protein for a second-type of SARS-COV-2 variant.

9 . A method for making the device of claim 1 , the method comprising:

transferring a composite film having a PMMA layer and a graphene layer onto the metal oxide coupled to the substrate resulting in a first composite substrate having a PMMA layer, a graphene layer, and a metal oxide layer;

immersing the first composite substrate in a solvent and thereby removing the PMMA layer resulting in a second composite substrate having a graphene layer and a metal oxide layer;

functionalizing the graphene layer of the second composite substrate with a chemical or biochemical linker; and

introducing a solvent containing the plurality of SARS-COV-2 receptors to a surface of the functionalized graphene layer and thereby binding the plurality of SARS-COV-2 receptors to the chemical or biochemical linker.

10 . The method of claim 9 , wherein functionalizing the graphene layer of the second composite substrate with a chemical or biochemical linker comprises functionalizing the graphene layer of the second composite substrate with an eta-6, eta-5, eta-4, eta-3, eta-2, or eta 1 chemistry such that a plurality of metal atoms each bind at a first end to the graphene layer and have a second end configured to bind with one of the plurality of SARS-COV-2 receptors.

11 . The method of claim 9 , further comprising:

prior to transferring the composite film having the PMMA layer and the graphene layer onto the metal oxide coupled to the substrate, growing the graphene layer on a metal foil using a low-pressure chemical vapor deposition;

spin-coating a PMMA solution onto the graphene layer on the metal foil, thereby resulting in a three-layered composite foil; and

etching the three-layered composite foil in a solvent until the metal foil dissolves thereby resulting in the composite film.

12 . The method of claim 9 , wherein growing the graphene layer on the metal foil comprises:

heating the metal foil to temperature above 900° C. in a chamber with a carbon containing gas for at least two minutes and at a pressure less than 10 mTorr; and

further oxidizing the metal foil using CVD with air or oxygen at temperature less than 500° C.

13 . The method of claim 9 , further comprising:

after immersing the first composite substrate in a solvent, annealing the second composite substrate to reduce contaminants.

14 . A method for using the device of claim 1 , the method comprising:

obtaining, via the Raman spectrometer, the first phononic energy from the target location on the graphene layer of the device to establish a testing baseline;

introducing a solution containing a saliva or a nasal sample to a surface of the functionalized graphene layer;

obtaining, via the Raman spectrometer, the second phononic energy from the target location of the graphene layer; and

determining whether a Raman shift between the first phononic energy and the second phononic energy exceeds a threshold value indicative of the presence of the target molecules.

15 . The method of claim 14 , wherein the threshold value is 0.8 cm −1 .

16 . The method of claim 14 , further comprising:

after introducing the solution containing the saliva or the nasal sample to the surface of the functionalized graphene layer, washing the device and thereby removing non-specifically bound molecules in the solution from the device.

17 . The method of claim 16 , wherein washing the device comprises:

washing the device with a phosphate-buffered saline solvent;

washing the device with a PBS solvent; and

washing the device with deionized water.

18 . The method of claim 17 , further comprising:

after washing the device, drying the device with nitrogen gas flow.

19 . The method of claim 14 , wherein the first phononic energy and the second phononic energy each correspond to a Raman 2D peak position.