title: Measurement of the position-dependent electrophoretic force on DNA in a glass nanocapillary.
abstract: The electrophoretic force on a single DNA molecule inside a glass nanocapillary depends on the opening size and varies with the distance along the symmetrical axis of the nanocapillary. Using optical tweezers and DNA-coated beads, we measured the stalling forces and mapped the position-dependent force profiles acting on DNA inside nanocapillaries of different sizes. We showed that the stalling force is higher in nanocapillaries of smaller diameters. The position-dependent force profiles strongly depend on the size of the nanocapillary opening, and for openings smaller than 20 nm, the profiles resemble the behavior observed in solid-state nanopores. To characterize the position-dependent force profiles in nanocapillaries of different sizes, we used a model that combines information from both analytical approximations and numerical calculations.
authors.affiliation: Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL , 1015 Lausanne, Switzerland.
authors.forename: Roman D
authors.initials: RD
authors.lastname: Bulushev
authors.forename: Lorenz J
authors.initials: LJ
authors.lastname: Steinbock
authors.forename: Sergey
authors.initials: S
authors.lastname: Khlybov
authors.forename: Julian F
authors.initials: JF
authors.lastname: Steinbock
authors.forename: Ulrich F
authors.initials: UF
authors.lastname: Keyser
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Radenovic
mesh_terms: D004247:DNA / Q000737:chemistry*; D019075:Electrophoresis, Capillary; D005898:Glass / Q000737:chemistry*; D055595:Mechanical Phenomena; D009038:Motion; D058608:Nanopores / Q000648:ultrastructure; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D052898:Optical Tweezers
chemical_list: D004247:DNA
keywords: DNA translocation; Single molecule measurements; force measurements; nanocapillary; optical tweezers; solid-state nanopore