Fabrication of nanopores using high electric fields

Patent metadata

Field	Value
Publication number	US-9777389-B2
Application number	US-201314399071-A
Country	US
Kind code	B2
Filing date	May 7, 2013
Priority date	May 7, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method is provided for fabricating a nanopore in a membrane. The method includes: applying an electric potential across the membrane, where value of the electric potential is selected to induce an electric field which causes a leakage current across the membrane; monitoring current flow across the membrane while the electric potential is being applied; detecting an abrupt increase in the leakage current across the membrane; and removing the electric potential across the membrane in response to detecting the abrupt increase in the leakage current.

First claim

What is claimed is:

1. A method for fabricating a single nanopore in a membrane, comprising:
selecting an electric potential that induces an electric field across an active area of the membrane, where the electric field has a value greater than 0.1 volt per nanometer across at least one point of the active area of the membrane prior to any removal of membrane material that would reduce thickness of the membrane in the active area;
applying the electric potential across the membrane comprised of a dielectric material and thereby causing removal of membrane material;
monitoring leakage current across the membrane while the electric potential is being applied across the membrane;
detecting an abrupt increase in the leakage current across the membrane while the electric potential is being applied across the membrane; and
removing the electric potential across the membrane in response to detecting the abrupt increase in the leakage current to stop the pore fabrication.

2. The method of claim 1 further comprises selecting an electric potential such that the electric field that approaches dielectric strength of the membrane material.

3. The method of claim 1 wherein detecting an abrupt increase in the leakage current further comprises determining a rate of change of the monitored current and comparing the rate of change to a threshold.

4. The method of claim 3 further comprises removing the electric potential when the rate of change of the monitored current exceeds the threshold, thereby stopping the fabrication.

5. The method of claim 1 wherein detecting an abrupt increase in the leakage current further comprises comparing a value of the monitoring current to a threshold and removing the electric potential when the value of the monitoring current exceeds a threshold, thereby stopping the fabrication.

6. The method of claim 1 further comprises
disposing the membrane between two reservoirs filled with a fluid containing ions, such that the membrane separates the two reservoirs and prevents the fluid from passing between the two reservoirs;
placing an electrode into each of the two reservoirs; and
generating the electric potential using the electrodes.

7. The method of claim 6 further comprises placing one of the two electrodes into direct contact with the membrane.

8. The method of claim 1 further comprises increasing the applied electric potential to reduce fabrication time.

9. The method of claim 1 further comprises increasing the electric field in the membrane to reduce fabrication time.

10. The method of claim 6 further comprises increasing concentration of ions in the fluid to reduce fabrication time.

11. The method of claim 6 further comprises increasing acidity of the fluid to reduce fabrication time.

12. The method of claim 6 further comprises increasing alkalinity of the fluid to reduce fabrication time.

13. The method of claim 6 further comprises changing acidity of the fluid in one reservoir in relation to the fluid in the other reservoir to change fabrication time.

14. The method of claim 6 further comprises adjusting acidity of the fluid on each side of the membrane to control geometry and surface charge characteristic of the pore.

15. The method of claim 6 further comprises adjusting polarity of the electric potential in the membrane to control geometry and surface charge characteristic of the pore.

16. The method of claim 1 wherein the nanopore is formed in the active area of the membrane.

17. A method for fabricating a single nanopore in a membrane, comprising:
selecting an electric potential that induces an electric field across an active area of the membrane, where the electric field has a value greater than 0.1 volt per nanometer across thickest part of the active area of the membrane prior to any removal of membrane material caused by the electric potential;
applying the electric potential across the membrane comprised of a dielectric material and thereby causing removal of membrane material;
monitoring leakage current across the membrane while the electric potential is being applied across the membrane;
detecting an abrupt increase in the leakage current across the membrane while the electric potential is being applied across the membrane; and
removing the electric potential across the membrane in response to detecting the abrupt increase in the leakage current to stop the pore fabrication.

18. A method for fabricating a single nanopore in a membrane, comprising:
selecting an electric potential that induces an electric field across an active area of the membrane, where the electric potential has a value greater than one volt and the electric field has a value greater than 0.1 volt per nanometer across the active are of the membrane;
applying the electric potential across the membrane comprised of a dielectric material and thereby causing removal of membrane material;
monitoring leakage current across the membrane while the electric potential is being applied across the membrane;
detecting an abrupt increase in the leakage current across the membrane while the electric potential is being applied across the membrane; and
removing the electric potential across the membrane in response to detecting the abrupt increase in the leakage current to stop the pore fabrication.

Assignees

• Univ Ottawa

Inventors

• Kwok Wing Hei
• Tabard-Cossa Vincent
• Briggs Kyle Alexander Zarkel

Classifications

• B01D2321/22

  Electrical effects · CPC title

• B81C1/00087

  Holes · 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

• B01D65/02

  Membrane cleaning or sterilisation {; Membrane regeneration} · CPC title

• C25F7/00

  Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects (for both electrolytic coating and removal C25D); Servicing or operating · CPC title