title: Slowing DNA Translocation in a Nanofluidic Field-Effect Transistor.
abstract: Here, 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.
authors.affiliation: Department 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.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department 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.
authors.forename: Levent
authors.initials: L
authors.lastname: Yobas
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D003198:Computer Simulation; D004247:DNA / Q000032:analysis*; D004058:Diffusion; D004566:Electrodes; D004574:Electromagnetic Fields; D007477:Ions / Q000737:chemistry; D044085:Microfluidics / Q000295:instrumentation; D058608:Nanopores; D017422:Sequence Analysis, DNA / Q000295:instrumentation; D013499:Surface Properties
chemical_list: D007477:Ions; D004247:DNA; D000537:Aluminum Oxide
keywords: DNA; field-effect; nanochannel; nanofluidic transistor; nanopore sequencing