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Direct Measurement of Single‐Molecule DNA Hybridization Dynamics with Single‐Base Resolution
Author(s) -
He Gen,
Li Jie,
Ci Haina,
Qi Chuanmin,
Guo Xuefeng
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201603038
Subject(s) - microsecond , folding (dsp implementation) , molecule , dna , a dna , base pair , oligonucleotide , materials science , chemical physics , molecular biophysics , chemistry , nanotechnology , crystallography , physics , optics , biochemistry , electrical engineering , organic chemistry , engineering
Herein, we report label‐free detection of single‐molecule DNA hybridization dynamics with single‐base resolution. By using an electronic circuit based on point‐decorated silicon nanowires as electrical probes, we directly record the folding/unfolding process of individual hairpin DNAs with sufficiently high signal‐to‐noise ratio and bandwidth. These measurements reveal two‐level current oscillations with strong temperature dependence, enabling us to determine the thermodynamic and kinetic properties of hairpin DNA hybridization. More importantly, successive, stepwise increases and decreases in device conductance at low temperature on a microsecond timescale are successfully observed, indicating a base‐by‐base unfolding/folding process. The process demonstrates a kinetic zipper model for DNA hybridization/dehybridization at the single base‐pair level. This measurement capability promises a label‐free single‐molecule approach to probe biomolecular interactions with fast dynamics.