Low noise ultrathin freestanding membranes composed of atomically-thin 2D materials

Patent metadata

Field	Value
Publication number	US-11041247-B2
Application number	US-202016781486-A
Country	US
Kind code	B2
Filing date	Feb 4, 2020
Priority date	Feb 20, 2015
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

The invention provides methods for direct growth of low noise, atomically thin freestanding membranes of two-dimensional monocrystalline or polycrystalline materials, such as transition metal chalcogenides including molybdenum disulfide. The freestanding membranes are directly grown over an aperture by reacting two precursors in a chemical vapor deposition process carried out at atmospheric pressure. Membrane growth is preferentially over apertures in a thin sheet of solid state material. The resulting membranes are one or a few atomic layers thick and essentially free of defects. The membranes are useful for sequencing of biopolymers through nanopores.

First claim

What is claimed is:

1. A device comprising (i) an ultrathin membrane comprising a two-dimensional transition metal adichalcogenide material containing at least one nanopore, and (ii) a sheet of solid state material having an aperture, wherein the membrane spans the aperture and is directly grown upon and attached to a surface of the sheet in an area surrounding the aperture and forms a leak-proof seal, and wherein each nanopore has a diameter in the range from about 0.3 nm to about 50 nm.

2. The device of claim 1 , wherein the two-dimensional transition metal dichalcogenide material is selected from the group consisting of GaS, GaSe, InS, InSe, HfS 2 , HfSe 2 , HfTe 2 , MoS 2 , MoSe 2 , MoTe 2 , NbS 2 , NbSe 2 , NbTe 2 , NiS 2 , NiSe 2 , NiTe 2 , PdS 2 , PdSe 2 , PdTe 2 , PtS 2 , PtSe 2 , PtTe 2 , ReS 2 , ReSe 2 , ReTe 2 , TaS 2 , TaSe 2 , TaTe 2 , TiS 2 , TiSe 2 , TiTe 2 , WS 2 , WSe 2 , WTe 2 , ZrS 2 , ZrSe 2 , and ZrTe 2.

3. The device of claim 1 , wherein the ultrathin membrane consists essentially of from one to several atomically thin sheets of the two-dimensional material.

4. The device of claim 3 , wherein the thickness of the ultrathin membrane is 1-2atomic layers.

5. The device of claim 1 , wherein the ultrathin membrane has a density of holes and atomic vacancies in the range from 0 to about 10 per nm 2 .

6. The device of claim 1 , wherein the ultrathin membrane has a background specific conductance, absent nanopores, of less than about 0.2 nS/μm 2 .

7. The device of claim 1 , wherein the ultrathin membrane spans a plurality of apertures in the solid state material.

8. The device of claim 7 , wherein the plurality of apertures is arranged in a two-dimensional array.

9. The device of claim 7 , wherein the ultrathin membrane comprises one or more nanopores within each aperture, and wherein each of said one or more nanopores has a diameter in the range from about 0.3 nm to about 50 nm.

10. The device of claim 1 , wherein the solid state material comprises a material selected from the group consisting of silicon nitride, silicon dioxide, hafnium oxide, titanium oxide, and aluminum oxide and has a thickness in the range from about 5 nm to about 10 μm.

11. The device of claim 1 , wherein the nanopore has an ion current noise level of less than 400 pA at 200 kHz bandwidth.

12. A method of detecting a molecule, the method comprising the steps of:
(a) providing the device of claim 1 comprising electrolyte solution on both sides of the ultrathin membrane, an electrode in each electrolyte solution, and a device for measuring ionic currents through the nanopore, wherein the electrolyte solution on one side of the ultrathin membrane comprises said molecule for detection;
(b) measuring a baseline ionic current through said nanopore; and
(c) observing blockage of the baseline ionic current by said molecule.

13. The method of claim 12 , wherein the molecule is a nucleic acid or a protein.

14. The method of claim 12 , wherein the molecule is detected as it moves through the nanopore of said ultrathin membrane.

15. The method of claim 12 , wherein a nucleotide sequence or an amino acid sequence of the molecule is determined.

16. The method of claim 12 , wherein a protein is detected, and the protein reduces the ionic current through the nanopore for about 2 msec to about 5 msec.

17. The method of claim 12 , wherein the ultrathin membrane is functionalized in a region surrounding the nanopore with a functionalization moiety having a binding affinity for said molecule.

18. The method of claim 17 , wherein the functionalization moiety is an enzyme or an antibody.

19. The method of claim 12 , wherein at least one of said electrolyte solutions comprises an ionic species, the other of said electrolyte solutions comprises a fluorescent indicator that binds said ionic species and changes its fluorescence in response thereto, and a current through the nanopore carried by said ion is detected via the fluorescence of the indicator.

20. The method of claim 19 , wherein the ion is Ca 2+ .

21. The device of claim 1 , wherein the membrane is directly grown to form a continuous sheet of membrane covering said surface.

22. The device of claim 1 , wherein the sheet of solid state material comprises a plurality of apertures or an array of apertures, and the membrane is directly grown to form a continuous sheet of membrane covering the plurality of apertures or the array of apertures.

Assignees

• Univ Northeastern

Inventors

• Waduge Pradeep
• Kar Swastik
• Wanunu Meni
• Larkin Joseph
• Bilgin Ismail

Classifications

• C25B9/23 Primary

  comprising ion-exchange membranes in or on which electrode material is embedded · CPC title

• C23C16/305

  Sulfides, selenides, or tellurides · CPC title

• C23C16/45517

  Confinement of gases to vicinity of substrate · CPC title

• C23C16/45514

  Mixing in close vicinity to the substrate · CPC title

• G01N33/48721 Primary

  Investigating individual macromolecules, e.g. by translocation through nanopores (Coulter counters in general G01N15/12; fabrication methods for nanoscale apertures B81B1/00; sequencing of nucleic acids C12Q1/68) · CPC title