nn6b00610_si_001.pdf (1.15 MB)
Slowing DNA Translocation in a Nanofluidic Field-Effect Transistor
journal contribution
posted on 2016-03-28, 00:00 authored by Yifan Liu, Levent YobasHere,
we present an experimental demonstration of slowing DNA translocation
across a nanochannel by modulating the channel surface charge through
an externally applied gate bias. The experiments were performed on
a nanofluidic field-effect transistor, which is a monolithic integrated
platform featuring a 50 nm-diameter in-plane alumina nanocapillary
whose entire length is surrounded by a gate electrode. The field-effect
transistor behavior was validated on the gating of ionic conductance
and protein transport. The gating of DNA translocation was subsequently
studied by measuring discrete current dips associated with single
λ-DNA translocation events under a source-to-drain bias of 1
V. The translocation speeds under various gate bias conditions were
extracted by fitting event histograms of the measured translocation
time to the first passage time distributions obtained from a simple
1D biased diffusion model. A positive gate bias was observed to slow
the translocation of single λ-DNA chains markedly; the translocation
speed was reduced by an order of magnitude from 18.4 mm/s obtained
under a floating gate down to 1.33 mm/s under a positive gate bias
of 9 V. Therefore, a dynamic and flexible regulation of the DNA translocation
speed, which is vital for single-molecule sequencing, can be achieved
on this device by simply tuning the gate bias. The device is realized
in a conventional semiconductor microfabrication process without the
requirement of advanced lithography, and can be potentially further
developed into a compact electronic single-molecule sequencer.