Molecule mass detection via field emission of electrons from membranes
AssigneeWisconsin Alumni Research Foundation
InventorRobert H. Blick
Life of this patent
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Abstract
An active detector and methods for detecting molecules, including large molecules such as proteins and oligonucleotides, at or near room temperature based on the generation of electrons via field emission (FE) and/or secondary electron emission (SEE). The detector comprises a semiconductor membrane having an external surface that is contacted by one or more molecules, and an internal surface having a thin metallic layer or other type of electron emitting layer. The kinetic energy of molecules contacting the semiconductor membrane is transferred through the membrane and induces the emission of electrons from the emitting layer. An electron detector, which optionally includes means for electron amplification, is positioned to detect the emitted electrons.
Claims27
A detector for detecting molecules, said detector comprising:
- a semiconductor membrane having an external surface for receiving said molecules, and an internal surface positioned opposite to said external surface, wherein said semiconductor membrane has a thickness of 5 nanometers to 50 microns;
- an electron emitting layer comprising a material selected from the group consisting of metals, doped semiconductors and doped diamond materials provided on the internal surface of said semiconductor membrane, wherein said emitting layer is a single continuous layer on the internal surface of said semiconductor membrane having a thickness of 5 nanometers to 10 microns, wherein the device does not contain any nanopillars attached to said semiconductor membrane, and wherein said emitting layer emits electrons when said semiconductor membrane receives said molecules;
- and
- an electron detector positioned to detect at least a portion of said emitted electrons.
A method for detecting molecules comprising the steps of:
- providing a detector comprising:
- a semiconductor membrane having an external surface for receiving said molecules, and an internal surface positioned opposite to said external surface, wherein said semiconductor membrane has a thickness of 5 nanometers to 50 microns;
- an electron emitting layer comprising a material selected from the group consisting of metals, doped semiconductors and doped diamonds provided on the internal surface of said semiconductor membrane, wherein said emitting layer is a single continuous layer on the internal surface of said semiconductor membrane having a thickness of 5 nanometers to 10 microns, wherein the device does not contain any nanopillars attached to said semiconductor membrane, and wherein said emitting layer emits electrons when said semiconductor membrane receives said molecules;
- contacting said molecules with the external surface of said membrane, thereby generating electrons emitted by said emitting layer;
- and
- detecting the emitted electrons.
A method of detecting molecules comprising the steps of:
- a) providing a detector having active detector areas, wherein each active detector area comprises:
- a semiconductor membrane having an external surface for receiving said molecules, and an internal surface positioned opposite to said external surface, wherein said semiconductor membrane has a thickness of 5 nanometers to 50 microns;
- an electron emitting layer comprising a material selected from the group consisting of metals, doped semiconductors and doped diamonds provided on the internal surface of said semiconductor membrane, wherein said emitting layer is a single continuous layer on the internal surface of said semiconductor membrane having a thickness of 5 nanometers to 10 microns, wherein the device does not contain any nanopillars attached to said semiconductor membrane, and wherein said emitting layer emits electrons when said semiconductor membrane receives said molecules;
- b) contacting said molecules with the external surface of said semiconductor membrane;
- c) converting the kinetic energy of said molecules contacting the external surface into lattice vibrations of the semiconductor membrane to generate phonons;
- d) transferring said phonons to said emitting layer, thereby generating electrons from the emitting layer in response to said transfer of phonons;
- and
- e) detecting the electrons emitted by said emitting layer.
Dependencies are inferred from the claim text.