Event
Special Bioengineering Seminar: Binqual Luan
Monday, April 12, 2010
11:00 a.m.
Room 1105, Jeong H. Kim Engineering Building
Professor Sameer Shah
sameer@umd.edu
Base-By-Base Ratcheting of Single Stranded DNA Through a Solid-State Nanopore
Presented by Binqual Luan
IBM Thomas J. Watson Research Center
The benefits of low-cost, high-throughput human genome sequencing to medical science has inspired recent experimental work focused on DNA translocation through solid-state nanopores. Given that microelectronic fabrication methods permit the integration of nano-electronics devices to sense each DNA base, the genetic code (DNA sequence) could be read out during translocation by measurement of transverse electrical current, voltage signal, ionic current or hydrogen-bond mediated tunneling signal generated by each base in turn. However, DNA translocation inside a solid nanopore remains poorly controlled and DNA moves too rapidly to be detected at the desired single-base resolution. Here I show using realistic atomistic modeling that the recently proposed DNA transistor can achieve single-base control. These simulation results and a simple theoretical model inspired by the numerical studies demonstrate that when pulled by an optical tweezer as in a single molecule experiment or driven by a biasing electric field as in a high-throughput screening mode, the DNA transistor allows single stranded DNA to transits a nanopore in a stick-slip or thermal ratchet-like fashion, i.e. DNA alternatively stops and advances quickly one nucleotide spacing. During a stick state, a DNA base could be positioned before a sensor for an accurate read-out. Ideally, the DNA transistor could be utilized in conjunction with a nanopore-based DNA sensing technology to achieve the goal of fast and cheap DNA sequencing.
