title: Dynamics of simultaneous, single ion transport through two single-walled carbon nanotubes: observation of a three-state system.
abstract: The ability to actively manipulate and transport single molecules in solution has the potential to revolutionize chemical synthesis and catalysis. In previous work, we developed a nanopore platform using the interior of a single-walled carbon nanotube (diameter = 1.5 nm) for the Coulter detection of single cations of Li(+), K(+), and Na(+). We demonstrate that as a result of their fabrication, such systems have electrostatic barriers present at their ends that are generally asymmetric, allowing for the trapping of ions. We show that above this threshold bias, traversing the nanopore end is not rate-limiting and that the pore-blocking behavior of two parallel nanotubes follows an idealized Markov process with the electrical potential. Such nanopores may allow for high-throughput linear processing of molecules as new catalysts and separation devices.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
authors.forename: Wonjoon
authors.initials: W
authors.lastname: Choi
authors.forename: Chang Young
authors.initials: CY
authors.lastname: Lee
authors.forename: Moon-Ho
authors.initials: MH
authors.lastname: Ham
authors.forename: Steven
authors.initials: S
authors.lastname: Shimizu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Strano
mesh_terms: D007477:Ions / Q000737:chemistry; D008672:Metals, Alkali / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D007477:Ions; D008672:Metals, Alkali; D037742:Nanotubes, Carbon