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Measuring a Frequency Spectrum for the Single-Molecule Interactions with A Confined Nanopore


A Nanopore analysis is a powerful technique for single molecule analysis by virtue of its electrochemical confined effects. As a single molecule translocates through the nanopore, the featured ionic current pattern in time scale contains single molecule characteristics including volume, charge and conformation properties. Although the characteristics of single molecule in nanopore have been written to the featured ionic current, extracting the dynamic information from complex current trace is still a big challenge. Here, we present a new nanopore method which employed Hilbert–Huang Transform (HHT) to study the vibration features and interactions of a single molecule during the dynamic translocation process through the nanopore confined space. The HHT method is specially developed for analyzing non-linear and non-stationary data that is highly compatible with nanopore data with frequency resolution of . To proof of concept, we applied HHT to measure the frequency response for the wild-type(WT) aerolysin and mutant K238E aerolysin nanopore with and without the presence of poly(dA)4, respectively. The energy–frequency–time distribution spectra domenstrate that the biological nanopore contribute greatly to the characteristics of high frequency component (> 2 kHz) in the current recording. Our results suggests a poly(dA)4 undergoes the relative more consistent and confined interactions with the K238E than the WT, leading to a prolonged the duration time. Therefore, the characteristics in frequency analysis could be regarded as a “ionic/molecule vibrational spectrum” inside nanopore which encodes the detailed behaviours of single-molecule weak interactions.

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Publication details

The article was accepted on 01 Mar 2018 and first published on 02 Mar 2018

Article type: Paper
DOI: 10.1039/C8FD00023A
Citation: Faraday Discuss., 2018, Accepted Manuscript
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    Measuring a Frequency Spectrum for the Single-Molecule Interactions with A Confined Nanopore

    S. Liu, M. Li, M. Li, Y. Wang, Y. Ying, Y. Wan and Y. Long, Faraday Discuss., 2018, Accepted Manuscript , DOI: 10.1039/C8FD00023A

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