Detecting Single-Nucleotides by Tunneling Current Measurements at Sub-MHz Temporal Resolution

Label-free detection of single-nucleotides was performed by fast tunneling current measurements in a polar solvent at 1 MHz sampling rate using SiO2-protected Au nanoprobes. Short current spikes were observed, suggestive of trapping/detrapping of individual nucleotides between the nanoelectrodes. Th...

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Bibliographic Details
Main Authors: Takanori Morikawa, Kazumichi Yokota, Sachie Tanimoto, Makusu Tsutsui, Masateru Taniguchi
Format: Article
Language:English
Published: MDPI AG 2017-04-01
Series:Sensors
Subjects:
Online Access:http://www.mdpi.com/1424-8220/17/4/885
Description
Summary:Label-free detection of single-nucleotides was performed by fast tunneling current measurements in a polar solvent at 1 MHz sampling rate using SiO2-protected Au nanoprobes. Short current spikes were observed, suggestive of trapping/detrapping of individual nucleotides between the nanoelectrodes. The fall and rise features of the electrical signatures indicated signal retardation by capacitance effects with a time constant of about 10 microseconds. The high temporal resolution revealed current fluctuations, reflecting the molecular conformation degrees of freedom in the electrode gap. The method presented in this work may enable direct characterizations of dynamic changes in single-molecule conformations in an electrode gap in liquid.
ISSN:1424-8220