Insertable nanoscale FET probe

• US 20070186628A1
• Filed: 02/10/2006
• Published: 08/16/2007
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Curry, Bo, Yi, Sungsoo
• Granted Patent: US 7,357,018 B2
• Time in Patent Office: Days
• US Class Current: 73/105
• 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: B82Y 35/00 Methods or apparatus for measurement or analysis of nanostructures
• CPC Class Codes: G01Q 60/30 Scanning potential microscopy
• CPC Class Codes: G01Q 60/42 Functionalisation
• CPC Class Codes: G01Q 70/12 Nanotube tips

Abstract

The nanoscale FET probe comprises a cantilever element and, at one end of the cantilever element, a nanowire that extends from the cantilever element. The nanowire is electrically connected to the cantilever element at at least one of the ends of the nanowire. The nanowire is capable of being coated with molecules of a capture agent along at least part of its length.

Claims

1. A nanoscale FET probe, comprising:

a cantilever element; and

a doped semiconductor nanowire extending from the cantilever element at an end of the cantilever element, the nanowire electrically connected to the cantilever element at at least one of the ends of the nanowire, the nanowire comprising a lateral surface capable of being coated with molecules of a capture agent along at least part of the length of the nanowire.

2. The nanoscale FET probe of claim 1, in which:

the nanowire extends substantially in a straight line from the cantilever element; and

the nanoscale FET probe is used in conjunction with an auxiliary conductive surface that is electrically contacted by a distal end of the nanowire, remote from the cantilever element.

3. The nanoscale FET probe of claim 2, in which:

the nanoscale FET probe additionally comprises a catalyst nanoparticle at the distal end of the nanowire, remote from the cantilever element; and

the catalyst nanoparticle electrically contacts the auxiliary conductive surface.

4. The nanoscale FET probe of claim 2, additionally comprising molecules of a capture agent coating the lateral surface of the nanowire.

5. The nanoscale FET probe of claim 4, additionally comprising means for monitoring an electrical property of the nanoscale FET probe that depends on binding between the molecules of a capture agent and an analyte of interest.

6. The nanoscale FET probe of claim 2, in which:

the cantilever element comprises semiconductor material and a crystalline growth surface; and

the semiconductor nanowire is epitaxial with respect to the growth surface.

7. The nanoscale FET probe of claim 2, in which:

a specimen is located on the auxiliary conductive surface; and

the nanowire extends through the specimen and the distal end of the nanowire is in electrical contact with the auxiliary conductive surface.

8. The nanoscale FET probe of claim 1, in which:

the nanowire is looped; and

the nanowire is electrically connected to the cantilever element at both ends thereof.

9. The nanoscale FET probe of claim 8, additionally comprising molecules of a capture agent coating the lateral surface of the nanowire.

10. The nanoscale FET probe of claim 9, additionally comprising means for monitoring an electrical property of the nanoscale FET probe that depends on binding between the molecules of the capture agent and an analyte of interest.

11. The nanoscale FET probe of claim 8, additionally comprising an electrical trace extending along the cantilever element into electrical contact with each of the ends of the nanowire.

12. A method for performing a measurement inside a specimen, the method comprising:

providing nanoscale FET probe comprising a cantilever element and a doped semiconductor nanowire extending from the cantilever element, the nanowire electrically connected to the cantilever element at at least one of the ends of the nanowire;

coating the nanowire along at least part of the length thereof with molecules of a capture agent;

moving the cantilever element to insert the nanowire into the specimen; and

monitoring an electrical property of the nanoscale FET probe to detect binding events between the capture agent molecules and an analyte of interest inside the specimen.

13. The method of claim 12, in which the monitoring comprises monitoring conductivity of the nanoscale FET probe.

14. The method of claim 12, in which the moving comprises:

providing an atomic force microscope;

mounting the cantilever element in the atomic force microscope; and

operating the atomic force microscope to move the cantilever element.

15. The method of claim 12, in which the moving comprises penetrating the specimen on a single side thereof.

16. The method of claim 15, in which:

the nanowire is looped; and

the nanowire is electrically connected to the cantilever element at both ends of the nanowire.

17. The method of claim 12, in which the moving comprises penetrating the specimen on opposite sides thereof.

18. The method of claim 17, in which:

the nanowire extends substantially in a straight line from the cantilever element;

the method additionally comprises;

providing an auxiliary conductive surface, and

placing the specimen on the auxiliary conductive surface;

the moving additionally comprises contacting the auxiliary conductive surface with the distal end of the nanowire, remote from the cantilever element, to establish an electrical circuit that includes the nanowire.

19. The method of claim 18, in which the monitoring comprises monitoring the electrical property of the nanoscale FET probe via the electrical circuit.

20. A method of making an insertable nanoscale FET probe, the method comprising:

providing a substrate comprising a crystalline growth surface;

growing a doped semiconductor nanowire extending from the crystalline growth surface; and

establishing an electrical circuit that includes the nanowire.

21. The method of claim 20, in which the establishing comprises:

providing an auxiliary conductive surface; and

contacting the auxiliary conductive surface with the distal end of the nanowire, remote from the substrate.

22. The method of claim 21, in which the establishing comprises forming the nanowire into a loop.

23. The method of claim 22, in which:

the growing comprises growing the nanowire in a direction of growth; and

the forming comprises changing the direction of growth at least once.

24. The method of claim 22, in which the forming comprises moving opposite ends of the nanowire into proximity.