Threading Immobilized DNA through a Solid-State Nanopore with a Tip

Nanopores have been of interest for scientific research in addition to medical applications since they have the ability to detect and characterize single biomolecules with potentially high throughput and low cost. The Scanning Probe Microscope (SPM) method has sub-nanometer spatial resolution. We have constructed a combined SPM-solid state nanopore apparatus to study the capture and release process of lambda-DNA by a voltage biased solid-state nanopore. By tethering the DNA to an fiber tip in ionic solution, we can control the position of one end of the DNA molecule precisely, allowing us to study the DNA capture and release distance from the nanopore. We also have detected DNA sticking to the nanopore mouth without translocation through, it produced small current blockage, and we can study this process with one DNA molecule repetitively. This tethered DNA nanopore sensing method will provide a means to slow DNA translocation, allowing more detailed features of single DNA molecules to be studied, and potentially can be used with all types of nanopores with single-biomolecule sensitivity at controlled translocation rates.