Optoelectronic control of solid-state nanopores
Optoelectronic control of solid-state nanopores and applications thereof. Nanopores are extremely sensitive single-molecule sensors. Electron beams have been used to fabricate synthetic nanopores in thin solid-state membranes with sub-nanometer resolution. Methods for controlling the translocation speed of biopolymers through solid-state nanopores and methods for unblocking clogged pores by illuminating nanopores are described.
1. A method for characterizing an analyte comprising:
providing a solid-state membrane comprising a nanopore submerged in a saline solution;
optoelectronically modifying a surface of the nanopore, while the solid-state membrane is submerged in the saline solution, to cause a measurable change in the nanopore ionic conductance not induced by a thermal effect;
applying an electric field across the solid-state membrane to generate an ion current through the nanopore and to translocate the analyte through the nanopore; and
detecting variations in the ion current and/or light emission from the analyte, wherein the variations in current and/or in the light emission correspond to interactions between the analyte and nanopore surface.
2. The method of claim 1 , wherein the change in nanopore ionic conductance due to the optoelectronical surface modification is an increase in conductance of at least 2%.
3. The method of claim 1 , wherein optoelectronically modifying the surface of the nanopore comprises illuminating the surface of the nanopore with radiant energy from a light source to induce an increase in conductance of the nanopore.
4. The method of claim 1 , wherein the analyte comprises a biopolymer.
5. The method of claim 4 , wherein the biopolymer comprises one of single-stranded DNA, double-stranded DNA, RNA, and a polypeptide.
6. The method of claim 3 , wherein the light source is a laser having a wavelength in the range from about 200-750 nm.
7. The method of claim 1 , wherein the solid state membrane comprises a semiconductor or insulating material that has energy levels accessible with visible light.
8. The method of claim 3 , further comprising chemically modifying the surface of the nanopore.
9. The method of claim 8 , wherein chemically modifying the surface of the nanopore comprises providing a chemical coating to create a gated pore that can be widened and narrowed by adjusting the radiant energy from the light source.
10. The method of claim 1 , wherein detecting variations in current comprises detecting variations in local ion current with electrodes disposed adjacent to the nanopore.
11. The method of claim 10 , wherein detecting variations in local ion current comprises detecting an open nanopore current and a blocked nanopore current, the blocked nanopore current varying with respect to interaction characteristics between the analyte and the nanopore.
12. The method of claim 11 , wherein the analyte comprises a DNA and the blocked nanopore current varies with respect to DNA length.