Concentrating a target molecule for sensing by a nanopore
Methods and related products are disclosed that improve the probability of interaction between a target molecule and a nanopore by capturing the target molecule on a surface comprising the nanopore. The captured target molecule, the nanopore, or both, are able to move relative to each other along the surface. When the leader of the target molecule is in proximity with the nanopore, interaction of the target portion of the target molecule with the nanopore occurs, thereby permitting sensing of the target portion. Confining the target molecule and nanopore in this manner leads to significantly enhanced interaction with the nanopore.
1. A method for concentrating target molecules for nanopore sensing, comprising:
capturing target molecules on a surface in contact with a cis reservoir,
wherein the surface comprises a nanopore penetrating through the surface and in fluid communication with a trans reservoir on an opposing side of the surface, and a hydrophobic domain, the hydrophobic domain comprising a diffusion barrier surrounding the nanopore and defining a shape selected for concentrating the captured target molecules in proximity to the nanopore upon flow of a buffer across the surface,
wherein each of the target molecules comprises a target portion, a hydrophobic capture element and a leader for interaction with the nanopore, and
wherein the hydrophobic capture elements are associated with, and capable of movement along, the hydrophobic domain of the surface to bring the leaders in proximity with the nanopore upon flow of a buffer across the surface;
flowing a buffer across the surface to concentrate the target molecules in proximity to the nanopore,
applying an electric field across the nanopore, thereby causing the leaders of the captured target molecules to interact with the nanopore, and the target portion to dissociate from the surface and translocate through the nanopore; and
sensing at least the target portion upon translocation through the nanopore.
2. The method of claim 1 , wherein the step of capturing the target molecule on the surface comprises contacting the surface with the target molecule, wherein the target molecule comprises, prior to the contacting step, the target portion, the hydrophobic capture element and the leader.
3. The method of claim 1 , wherein the step of capturing the target molecule on the surface comprises linking the hydrophobic capture element associated with the surface to the target portion and leader, thereby capturing the target molecule on the surface.
4. The method of claim 1 , wherein the nanopore is a biological nanopore.
5. The method of claim 1 , wherein the surface is a lipid bilayer.
6. The method of claim 1 , wherein the surface is a solid-state or synthetic membrane.
7. The method of claim 1 , wherein the target portion comprises nucleic acids.
8. The method of claim 1 , wherein the target portion comprises a linear polymer.
9. The method of claim 1 , wherein the target portion comprises a molecular bar code.
10. The method of claim 1 , wherein the target portion comprises linkers and a nucleotide sequence complementary to a target nucleic acid sequence, wherein the combined linear length of the linkers and nucleotide sequence is longer than the linear length of the target nucleic acid sequence.
11. The method of claim 1 , wherein the leader is a hydrophilic polymer.
12. The method of claim 1 , wherein the hydrophobic capture element is an aliphatic hydrocarbon.
13. The method of claim 1 , wherein the target molecules comprises two or more hydrophobic capture elements.