Compositions, devices, systems, and methods for using a nanopore
Devices and methods that can detect and control an individual polymer in a mixture is acted upon by another compound, for example, an enzyme, in a nanopore are provided. The devices and methods also determine (˜>50 Hz) the nucleotide base sequence of a polynucleotide under feedback control or using signals generated by the interactions between the polynucleotide and the nanopore. The invention is of particular use in the fields of molecular biology, structural biology, cell biology, molecular switches, molecular circuits, and molecular computational devices, and the manufacture thereof.
1. A method for controlling insertion of a pore molecule into a thin film of a device, the thin film separating two pools of a liquid medium, the method comprising:
(a) providing, in one of the two pools, an amount of pore molecules sufficient to form at least a single pore in said thin film by insertion of a pore molecule into the thin film;
(b) providing a circuit comprising electrodes in the two pools, thereby providing a potential difference across the thin film, said circuit further connected to voltage control logic;
(c) detecting insertion of a pore molecule into the thin film by sensing a change in a transport property with the voltage control logic; and
(d) adjusting the potential difference in response to the change in a measured transport property resulting from insertion of the pore molecule, to thereby decrease the possibility of insertion of a second pore molecule into said thin film.
2. A method according to claim 1 wherein insertion of the pore molecule is detected by a finite state machine.
3. A method according to claim 2 wherein the adjusting of the potential difference is carried out by the finite state machine.
4. A method according to claim 1 wherein the thin film is a lipid bilayer.
5. A method according to claim 1 wherein the measured transport property is ion current flow.
6. A method according to claim 1 wherein the device comprises an array of elements comprising thin films and individual cis and trans chambers, wherein a common electrode is provided in the cis chamber and electrodes are provided in each of the trans chambers for providing a potential difference across each thin film, further comprising steps of:
measuring a transport property across each thin film, and detecting the insertion of a nanopore into each thin film on the basis of a change in the measured transport property; and
individually adjusting the potential difference across each thin film in response to the change in transport property to decrease the possibility of insertion of a second nanopore into said each thin film.