title: DNA Translocation in Nanometer Thick Silicon Nanopores.
abstract: Solid-state nanopores are single-molecule sensors that detect changes in ionic conductance (ΔG) when individual molecules pass through them. Producing high signal-to-noise ratio for the measurement of molecular structure in applications such as DNA sequencing requires low noise and large ΔG. The latter is achieved by reducing the nanopore diameter and membrane thickness. While the minimum diameter is limited by the molecule size, the membrane thickness is constrained by material properties. We use molecular dynamics simulations to determine the theoretical thickness limit of amorphous Si membranes to be ∼1 nm, and we designed an electron-irradiation-based thinning method to reach that limit and drill nanopores in the thinned regions. Double-stranded DNA translocations through these nanopores (down to 1.4 nm in thickness and 2.5 nm in diameter) provide the intrinsic ionic conductance detection limit in Si-based nanopores. In this regime, where the access resistance is comparable to the nanopore resistance, we observe the appearance of two conductance levels during molecule translocation. Considering the overall performance of Si-based nanopores, our work highlights their potential as a leading material for sequencing applications.
authors.affiliation: †Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Julio A
authors.initials: JA
authors.lastname: Rodríguez-Manzo
authors.affiliation: †Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.|‡Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: Puster
authors.affiliation: §Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
authors.forename: Adrien
authors.initials: A
authors.lastname: Nicolaï
authors.affiliation: §Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.|∥Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
authors.forename: Vincent
authors.initials: V
authors.lastname: Meunier
authors.affiliation: †Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Marija
authors.initials: M
authors.lastname: Drndić
mesh_terms: D004247:DNA / Q000737:chemistry*; D004553:Electric Conductivity; D056004:Molecular Dynamics Simulation; D058608:Nanopores; D036103:Nanotechnology / Q000295:instrumentation; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004247:DNA; D012825:Silicon
keywords: DNA; EELS; STEM; amorphous silicon; nanopore; single-molecule sensor; thin membrane