Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

doi:10.1073/pnas.0500081102

Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

^*Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden; and ^†Unité Mixte de Recherche 168, Institut Curie, 26 Rue d'Ulm, F-75248 Paris Cédex 05, France

Edited by George M. Whitesides, Harvard University, Cambridge, MA, and approved May 9, 2005 (received for review January 5, 2005)

Abstract

We demonstrate a complete nanotube electrophoresis system (nanotube radii in the range of 50 to 150 nm) based on lipid membranes, comprising DNA injection, single-molecule transport, and single-molecule detection. Using gel-capped electrodes, electrophoretic single-file transport of fluorescently labeled dsDNA molecules is observed inside nanotubes. The strong confinement to a channel of molecular dimensions ensures a detection efficiency close to unity and identification of DNA size from its linear relation to the integrated peak intensity. In addition to constituting a nanotechnological device for identification and quantification of single macromolecules or biopolymers, this system provides a method to study their conformational dynamics, reaction kinetics, and transport in cell-like environments.

Footnotes

↵ ‡ To whom correspondence should be addressed. E-mail: orwar{at}chembio.chalmers.se.
Author contributions: M.T., B.\A., and O.O. designed research; M.T. performed research; M.T., B.\A., J.O., J.-F.J., P.D., and O.O. analyzed data; M.T., B.\A., J.O., J.-F.J., P.D., and O.O. wrote the paper; and J.O. performed simulations.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviation: NVN, nanotube-vesicle network.