A 150 nm ultraviolet excitation volume on a porous silicon membrane for direct optical observation of dna coil relaxation during capture into nanopores

Hirohito Yamazaki, Keiko Esashika, Toshiharu Saiki

Research output: Contribution to journalLetterpeer-review

4 Citations (Scopus)

Abstract

We report the first optical observation of DNA coil relaxation during capture into silicon nanopores, which was achieved using fluorescence microscopy with a 150 nm observation volume. Compared with our previous results, the gradual increase and steep decay of the fluorescence signal can be interpreted as the capture of the DNA molecule and its translocation through the nanopore, respectively. Furthermore, a longer dwell time was obtained when we used a nanoporous membrane with high porosity. From a numerical calculation of the electric field distribution in the vicinity of the nanopore, we concluded that a ‘biased’ electric field, as well as funneling of the field into surrounding nanopores, hinders DNA coil relaxation. Our result showed the capability of a UV excitation volume on a silicon membrane for observation of DNA capture into nanopores at a single-molecule level.

Original languageEnglish
Article number011001
JournalNano Futures
Volume1
Issue number1
DOIs
Publication statusPublished - 2017 Jun 1

Keywords

  • DNA dynamics
  • Fluorescence
  • Nano-optics
  • Nanopore

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Electrical and Electronic Engineering

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