Whole virus quantum mechanical tunneling current and electronic sensors
A field effect transistor (FET) biosensor for virus detection of a selected virus within a sample volume is disclosed. The FET comprises a semiconductor substrate, a source and drain electrode on the substrate, the electrodes spaced to form a channel. A gate electrode carried on the substrate and located in the channel between the source and drain electrodes. An insulating layer is coupled to a top surface of the gate electrode and a bottom surface of the source and drain electrodes, with an open channel above the insulating layer. A channel material is coupled to the insulating layer. Aptamers are oriented within the open channel to bind to the channel material and with the selected virus to enable a detection of the selected virus by the FET biosensor based on a change in drain-source current at a selected gate voltage.
1. A vertical nano gap tunneling current biosensor, comprising:
a semiconductor substrate;
a first electrode oriented on the semiconductor substrate and configured to be connected to a parameter analyzer, the first electrode having a conductive sample surface including molecular recognition groups attached to the surface which are configured to bind with a selected virus, and having an open region located above the first electrode such that the a sample can be introduced onto the surface from outside of the biosensor;
a second electrode spaced from the first electrode with a portion of the electrode protruding into the open region to form a nano-gap between the first electrode and the second electrode, the nano-gap having a tunneling gap distance to enable a tunneling current between the first electrode and the second electrode when a voltage differential is provided between the first electrode and the second electrode; and
a dielectric layer separating the first electrode and the second electrode,
wherein the parameter analyzer is configured to detect a change in the tunneling current through the nano-gap over a range in voltage and the change in the tunneling current is used to identify when the selected virus is bound to the molecular recognition groups.
2. The vertical nano gap tunneling current biosensor of claim 1 , wherein the semiconductor substrate comprises silicon and a passivation layer is oriented between the semiconductor substrate and the first electrode.
3. The vertical nano-gap tunneling current biosensor of claim 1 , wherein the molecular recognition groups include at least one of aptamers, antibodies, and antigens.
4. The vertical nano-gap tunneling current biosensor of claim 1 , wherein the selected virus is either SARS-CoV-2 or ZIKA.
5. The vertical nano-gap tunneling current biosensor of claim 1 , wherein the first and second electrodes are formed of gold.
6. The vertical nano-gap tunneling current biosensor of claim 1 , wherein the dielectric layer is silicon dioxide.
7. The vertical nano-gap tunneling current biosensor of claim 1 , further including a hydrophobic layer coated on a top surface of the second electrode.
8. The vertical nano-gap tunneling current biosensor of claim 1 , wherein the tunneling gap distance is formed to have a selected gap size based on the selected virus and the tunnel gap distance is orthogonal to a plane of the conductive sample surface.