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 journalLetter

    3 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

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

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