title: Coulomb forces on DNA polymers in charged fluidic nanoslits.
abstract: We investigate the repulsive electrostatic interactions between a DNA polyelectrolyte and the charged walls of a fluidic nanoslit. The scaling of the DNA coil size with the physical slit height revealed electrostatic depletion regions that reduced the effective slit height. These regions exceeded the Debye screening length of the buffer, λ(D)(buffer), and saturated at ≈ 50 nm when λ(D)(buffer) reached 10 nm. We explain these results by modeling a semiflexible charged rod near a charged wall and the electrostatic screening by the polyelectrolyte. These results demonstrate the surprisingly long range over which a nanofluidic device can exert field-effect control over confined molecules.
authors.affiliation: Physics Department, Brown University, Providence, Rhode Island, USA.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Ren
authors.forename: Derek
authors.initials: D
authors.lastname: Stein
mesh_terms: D004247:DNA / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D011108:Polymers / Q000737:chemistry*; D012492:Salts / Q000737:chemistry; D055672:Static Electricity
chemical_list: D004573:Electrolytes; D011108:Polymers; D012492:Salts; D004247:DNA