Electronic label free detection of DNA complexes using nanogap
AssigneeInternational Business Machines Corporation
InventorsVenkat K. Balagurusamy, Stanislav Polonsky
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Abstract
A technique for electrical detection of a molecule is provided. A fluidic bridge is formed between a nanopipette and a fluid cell, where the molecule is in the nanopipette. A voltage difference is applied between the nanopipette and the fluid cell, where the fluid cell contains an electrolyte solution. Entry of the molecule into the fluidic bridge is determined by detecting a fore pulse. The fluidic bridge between the nanopipette and the fluid cell is broken to form a nanogap. In response to waiting a time interval, the fluidic bridge is reformed between the nanopipette and the fluid cell to close the nanogap. The molecule is determined to exit the nanopipette by detecting an after pulse.
Claims13
A method for electrical detection of a molecule, the method comprising:
- dipping a tip of a nanopipette into an electrolyte solution in a fluid cell, in order to form a fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell, wherein the molecule is in the nanopipette;
- applying a voltage difference between the nanopipette and the fluid cell, wherein the fluid cell contains the electrolyte solution;
- determining entry of the molecule into the fluidic bridge by detecting a fore pulse;
- breaking the fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell to form a nanogap by moving the nanopipette away from the fluid cell such that a middle portion of the molecule is in the nanogap, wherein no electrolyte solution is in the nanogap, wherein the fluidic cell is a container having an open top, wherein the nanopipette is positioned vertically above the open top of the fluidic cell to create the nanogap, wherein a nanopipette width of the nanopipette is less than a width of the open top of the fluidic cell;
- recognizing that the nanogap is created by detecting a pulse break, no ionic current being detected for the pulse break;
- in response to waiting a time interval, reforming the fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell to close the nanogap;
- and
- determining that the molecule completely exits the nanopipette to reside in the fluid cell by detecting an after pulse.
A method for electrical detection of binding of a protein to a molecule, the method comprising:
- dipping a tip of a nanopipette into an electrolyte solution in a fluid cell, in order to form a fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell, wherein the molecule and the protein are in the nanopipette;
- applying a voltage difference between the nanopipette and the fluid cell, wherein the fluid cell contains an electrolyte solution;
- determining entry of the molecule into the fluidic bridge by detecting a fore pulse;
- breaking the fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell to form a nanogap by moving the nanopipette away from the fluid cell such that a middle portion of the molecule is in the nanogap, wherein no electrolyte solution is in the nanogap, wherein no electrolyte solution is in the nanogap, wherein the fluidic cell is a container having an open top, wherein the nanopipette is positioned vertically above the open top of the fluidic cell to create the nanogap, wherein a nanopipette width of the nanopipette is less than a width of the open top of the fluidic cell;
- recognizing that the nanogap is created by detecting a pulse break, no ionic current being detected for the pulse break;
- in response to waiting a time interval, reforming the fluidic bridge between the nanopipette and the electrolyte solution in the fluid cell to close the nanogap;
- and
- determining that the protein is bound to the molecule by detecting an after pulse when the molecule completely exits the nanopipette to reside in the fluid cell.
Dependencies are inferred from the claim text.