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Slowing DNA Translocation in a Nanofluidic Field-Effect Transistor
1Department of Electronic and Computer Engineering, ‡Division of Biomedical Engineering, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong S. A. R.
ACS Nano
|March 29, 2016
Summary
Researchers demonstrated slowing DNA translocation through a nanochannel using a field-effect transistor. Applying a positive gate bias significantly reduced DNA translocation speed, crucial for DNA sequencing applications.
Area of Science:
- Nanotechnology
- Biophysics
- Molecular Electronics
Background:
- DNA translocation through nanoscale channels is key for single-molecule analysis.
- Controlling translocation speed is essential for applications like DNA sequencing.
Purpose of the Study:
- To experimentally demonstrate the slowing of DNA translocation using a tunable gate bias.
- To investigate the effect of surface charge modulation on DNA transport dynamics.
Main Methods:
- Utilized a nanofluidic field-effect transistor with a 50 nm alumina nanocapillary.
- Applied source-to-drain bias and modulated channel surface charge with a gate electrode.
- Measured single DNA translocation events and analyzed translocation times using a diffusion model.
Main Results:
- A positive gate bias markedly slowed DNA translocation speed, reducing it by an order of magnitude.
- Translocation speed decreased from 18.4 mm/s (floating gate) to 1.33 mm/s (9 V gate bias).
- Demonstrated field-effect transistor behavior for ionic conductance and protein transport.
Conclusions:
- Dynamic and flexible regulation of DNA translocation speed is achievable by tuning gate bias.
- This method offers a pathway for developing compact electronic single-molecule sequencers.
- The device fabrication uses conventional semiconductor processes, avoiding advanced lithography.
