Methods and Devices for Detection of THC
In one aspect, a method of detecting tetrahydrocannabinol (THC) in a sample is disclosed, which comprises bringing the sample into contact with a graphene layer functionalized with an antibody exhibiting specific binding to THC, applying a time-varying electric field to said antibody-functionalized graphene layer, monitoring electrical resistance of said graphene layer in response to interaction with said sample, and detecting presence of THC in the sample by detecting a change in said electrical resistance indicative of interaction of THC with said anti-body functionalized graphene layer.
1 - 24 . (canceled)
25 . A system for detecting THC in a sample, comprising:
a sensor, comprising:
a substrate,
a graphene layer deposited on a surface of said substrate, said graphene layer being functionalized with a plurality of antibodies exhibiting specific binding to THC,
at least one pair of electrically conductive pads coupled to said anti-body-functionalized graphene layer for measuring an electrical property of said anti-body-functionalized graphene layer; and
a reference electrode disposed in proximity to said anti-body functionalized graphene layer.
26 . The system of claim 25 , wherein the reference electrode is positioned above the graphene layer.
27 . The system of claim 25 , wherein a distance between the reference electrode and the graphene layer is in the range of approximately 50 micrometers to approximately 3 millimeters.
28 . The system of claim 25 , wherein the distance between the reference electrode and the graphene layer is in the range of approximately 1 millimeter to approximately 2 millimeters.
29 . The system of claim 25 , wherein the reference electrode is configured to generate a time-varying electric field at an interface of the graphene layer and the sample in contact with the graphene layer.
30 . The system of claim 25 , further comprising an AC voltage source for applying an AC voltage to said reference electrode.
31 . The system of claim 30 , wherein the applied AC voltage source creates a time-varying electric field in a space between the reference electrode and the functionalized graphene layer.
32 . The system of claim 30 , wherein said AC voltage source is configured to apply an AC voltage having a frequency in a range of about 1 kHz to about 1 MHz.
33 . The system of claim 32 , wherein said AC voltage has an amplitude in a range of about 1 millivolts to about 3 volts.
34 . The system of claim 25 , further comprising an DC voltage source for applying a DC offset voltage to said reference electrode.
35 . the system of claim 25 , wherein the graphene layer consists of a monolayer of carbon atoms.