Ultrasensitive biosensors

• US 10,563,252 B2
• Filed: 08/28/2018
• Issued: 02/18/2020
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: University of Hawai'i
• Original Assignee: University of Hawai'i
• Inventors: Holm-Kennedy, James
• Primary Examiner(s): Dickey, Thomas L
• Application Number:
  US16/114,694
• Publication Number:
  US 20190048398A1
• Time in Patent Office: 539 Days
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: C12Q 1/686 Polymerase chain reaction [PCR]
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
• CPC Class Codes: H01L 29/0665 the shape of the body defining a nanostructure nanotechnology per se B82B
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66439 with a one- or zero-dimensional channel, e.g. quantum wire FET, in-plane gate transistor [IPG], single electron transistor [SET], striped channel transistor, Coulomb blockade transistor with an active layer made of a group 13/15 material H01L29/66469

Abstract

The present invention is a biosensor apparatus that includes a substrate, a source on one side of the substrate, a drain spaced from the source, a conducting channel between the source and the drain, an insulator region, and receptors on a gate region for receiving target material. The receptors are contacted for changing current flow between the source and the drain. The source and the drain are relatively wide compared to length between the source and the drain through the conducting channel.

Claims

1. A biosensor apparatus comprising:

a substrate,

a source on one side of the substrate,

a temperature sensor and a pH sensor on the substrate,

a drain spaced from the source,

a conducting channel between the source and the drain,

an insulator region,

receptors on a gate region for receiving target material,

wherein the receptors are contacted for changing current flow between the source and the drain, and

wherein the conducting channel and the insulator region and the gate region have relatively long length between the source and the drain compared to width of the source, the drain, the conducting channel, the insulator region and the gate region.

2. The apparatus of claim 1, wherein the target materials are biological materials.

3. A method of sensing target materials comprising:

providing a substrate,

providing a source in or on the substrate,

providing a drain in or on the substrate spaced from the source,

providing a conducting channel in or on the substrate between the source and the conducting channel,

providing an insulator region on the conducting channel and on the substrate,

providing a temperature sensor and a pH sensor on the substrate,

providing a gate region on the insulator region, and

providing receptors on the gate region and controlling relative widths and lengths of the source, the drain, the conducting channel, the insulator region and the gate region and thereby controlling sensitivity to the target materials.

4. The method of claim 3, further comprising providing a circuit wherein the output of the circuit provides a parameter for providing a measurement of sensor response to target binding.

5. A sensor apparatus comprising:

a substrate,

a temperature sensor and a pH sensor on the substrate,

an epitaxial layer disposed on the substrate,

a first ohmic contact on the substrate,

a second ohmic contact on the substrate spaced from the first ohmic contact,

a conducting mesa etched in the epitaxial layer between the first and second ohmic contacts,

a functionalized surface overlying the epitaxial layer,

a biochemical receptor region on the functionalized surface, and

conducting interconnections connected to the first and second contacts.

6. The apparatus of claim 5, wherein the conducting interconnections extend through the epitaxial layer.

7. The apparatus of claim 5, wherein a PN junction is formed between the epitaxial layer and the substrate.

8. The apparatus of claim 5, further comprising a depletion region in the substrate under the conducting mesa, and a back gate biasing circuit connected to the substrate.

9. The apparatus of claim 5, wherein the epitaxial layer is doped with a different P or N type from the substrate.

10. The apparatus of claim 5, wherein the epitaxial layer is a first epitaxial layer and further comprising a second epitaxial layer positioned on the substrate between the substrate and the first epitaxial layer.

11. The apparatus of claim 5, wherein the conducting mesa etched epitaxial layer is a polysilicon N or P type resistor.

12. The apparatus of claim 11, further comprising insulators on the polysilicon resistor.

13. The apparatus of claim 11, wherein the functionalized surface is a resistor protective layer and wherein the receptors are recognition elements attached to the resistor protective layer.

14. The apparatus of claim 13, wherein multiple distinct recognition elements are attached to the resistor protective layer for testing distinct target materials.

15. The apparatus of claim 14, wherein the resistor is constructed with specific etched mesa constructions near the distinct recognition elements.

16. The apparatus of claim 11, wherein the resistor is a meanderline resistor.

17. The apparatus of claim 5, further comprising an array of sensors polysilicon N or P type resistors.

18. The apparatus of claim 17, further comprising addressing circuitry connecting the array of sensors, and further comprising an array output.

19. The apparatus of claim 5, further comprising a feedback system for temperature control and a heater resistor.