Fabricated solid-state nanopore chips are used to probe individual single stranded DNA (ssDNA) homopolymers. Based on the analysis of the current blockage caused by DNA translocation through a voltage-biased nanopore, we discovered that the hydrodynamic diameter of ssDNA homopolymer helix is comparable to that of double stranded DNA (dsDNA) helix. This proof-of-principle demonstration shows tha...

We demonstrate a new nanoscale system consisting of a nanotube threaded through a nanopore in aqueous solution. Its electrical and mechanical properties are sensitive to experimentally controllable conformational changes on sub-Angstrom length scales. Ionic current transport through a nanopore is significantly suppressed by the threading nanotube and the mechanical interactions between the nano...

Reducing a DNA molecule's translocation speed in a solid-state nanopore is a key step toward rapid single molecule identification. Here we demonstrate that DNA translocation speeds can be reduced by an order of magnitude over previous results. By controlling the electrolyte temperature, salt concentration, viscosity, and the electrical bias voltage across the nanopore, we obtain a 3 base/micros...

Switchable ion channels that are made of membrane proteins play crucial role in cellular circuits. Thereby synthetic nanofluidic channels attract great interest owing to the novel ion transport properties that are helpful for understanding the biological ion channels and for the promising applications on ultrasensitive molecular detection and separation [1]. Here we report a synthetic nanopore-...

We present a molecular-level simulation study of the effects of confinement on chemical reaction equilibrium in nanoporous materials. We use the reaction ensemble Monte Carlo (RxMC) method to investigate the effects of temperature, nanopore size, bulk pressure, and capillary condensation on the nitric oxide dimerization reaction in a model carbon slit nanopore in equilibrium with a bulk reservo...

Monitoring the progress of DNA molecules through a membrane pore has been postulated as a method for sequencing DNA for several decades. Recently, a nanopore-based sequencing instrument, the Oxford Nanopore MinION, has become available, and we used this for sequencing the Saccharomyces cerevisiae genome. To make use of these data, we developed a novel open-source hybrid error correction algorit...

Unlike the overwhelming majority of nanopore sensors that are based on the measurement of a transpore ionic current, here we introduce a potentiometric sensing scheme and demonstrate its application for the selective detection of nucleic acids. The sensing concept uses the charge inversion that occurs in the sensing zone of a nanopore upon binding of negatively charged microRNA strands to posit...

DNA methylation is an epigenetic modification of DNA in which methyl groups are added at the 5-carbon position of cytosine. Aberrant DNA methylation, which has been associated with carcinogenesis, can be assessed in various biological fluids and potentially can be used as markers for detection of cancer. Analytically sensitive and specific assays for methylation targeting low-abundance and frag...

We show that a semiconductor membrane made of two thin layers of opposite (nand p-) doping can perform electrically tunable ion current rectification and filtering in a nanopore. Our model is based on the solution of the 3D Poisson equation for the electrostatic potential in a double-cone nanopore, combined with a transport model. It predicts that for appropriate biasing of the membraneelectrol...

An apparatus that integrates solid-state nanopore ionic current measurement with a scanning-probe microscope is developed. When a micrometer-scale scanning-probe tip is near a voltage-biased nanometer-scale pore (10–100 nm), the tip partially blocks the flow of ions to the pore and increases the pore access resistance. The apparatus records the current blockage caused by the probe tip and the l...