Abstract

Nanosensor Chips for the Single-Molecule Sequencing of DNA and RNA

Steve Soper, Foundation Distinguished Professor; Director, Center of BioModular Multi-scale System for Precision Medicine, Adjunct Professor, Ulsan National Institute of Science & Technology, The University of Kansas

We are generating a single-molecule DNA/RNA sequencing platform that can acquire sequencing information with high accuracy (>99%) at unprecedented throughputs (106 nt/s). The technology employs a fluidic chip populated with nanosensors that read the identity of individual mononucleotides from their characteristic flight-time through a 2-dimensional (2D) nanochannel (~50 nm in width and depth; >10 µm in length) and their current transient amplitudes. The nanosensors are fabricated in a thermoplastic via nanoimprint lithography (NIL). The mononucleotides are generated from an intact DNA fragment using a highly processive exonuclease, which is covalently anchored to a plastic support (500 nm in diameter) contained within a bioreactor that sequentially feeds mononucleotides into a 2D nanochannel. The identity of the mononucleotides is deduced from a molecular-dependent flight-time through the 2D nanochannel that is related to the electrophoretic mobility of that molecule. The flight time is read in a label-less fashion by measuring current transients (i.e., resistive pulse sensing) induced by a single mononucleotide when it travels through a constriction possessing molecular dimensions (<10 nm in diameter) and poised at the input/output ends of the flight tube. In this presentation, our efforts in building these nanosensors using NIL in thermoplastics will be discussed. We will also talk about the detection of single molecules using NIL-produced nanopores. Also, surface modifications of plastics for the immobilization of biologics, such as exonucleases, will be discussed and their enzymatic performance when surface immobilized. Finally, information on the manipulation of single DNA molecules using nanofluidic circuits that uses nano-scale features to shape electric fields will be presented.