Abstract
Biotechnology A prospective alternative approach to direct DNA sequencing is to monitor changes in ion current as a DNA strand translocates through a nanopore. However, the speed of the translocation process—about 1 base per microsecond—exceeds the response speed of the electronics needed to amplify the small changes in current when measured with microelectrodes in solution. A field-effect transistor (FET) close to the pore should have sufficient speed and sensitivity to resolve these signals, but charge signals might be screened by the high ionic strength of the solvent. Xie et al. fabricated a silicon nanowire FET with a very short channel length (200 nm) on a silicon nitride membrane. They then etched a nanopore (7 to 10 nm in diameter) through the membrane and along the edge of the nanowire, and measured ion currents and FET signals for translocation of 2.6-kbp double-stranded DNA in 1 M KCl. The signal from the nanowire FET tracked that of the ion current measurement if a hundredfold dilution (10 mM KCl) was used in the receiving solution. Measurement of base-pair changes for single-stranded DNA will require further improvements in signal-to-noise ratio and spatial resolution. Nat. Nanotechnol. 10.1038/nnano.2011.217 (2011).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
