Abstract

Polymer-based Nanosensors for Single-Molecule Sequencing

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 (>95%) at unprecedented throughputs (106 bases s-1). The technology employs high density arrays of 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) 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 solid support contained within a bioreactor that sequentially feeds mononucleotides into the 2D nanochannel. The identity of the mononucleotides is deduced from a molecular-dependent flight-time through the 2D nanochannel. The flight time is read in a label-free fashion by measuring current transients (i.e., resistive pulse sensing) induced by a single mononucleotide when it travels through a constriction with molecular dimensions (<5 nm in effective diameter) poised at the input/output ends of the flight tube. In this presentation, our efforts on building these nanosensors using NIL in thermoplastics will be discussed and the detection of single molecules using electrical transduction with their identity deduced from the associated flight time provided. Also, surface modifications of thermoplastics for the immobilization of biologics, such as exonucleases, will be discussed as well as the activity of biological enzymes when immobilized to a plastic support. Finally, information on the manipulation of single DNA molecules using nanofluidic circuits will be presented that takes advantage of forming unique nanoscale features to shape electric fields for DNA manipulation and serves as the operational basis of the nanosensing platform.