Arizona State University,
Keywords: Nanopore, quantum tunneling, nanofluidic chip, biosensor
Summary:The COVID-19 pandemic shows the prominent needs of fast and early detection of biomarkers at low cost. Current test methods produce a large number of false negatives due to the limited sensitivity. One way to address this issue is to have an analytical method that can detect low copy numbers of biomolecules, or of a low limit of detection (LoD). Single-molecule-detection based techniques is an attractive candidate. We designed a new nanopore chip that can precisely deliver, manipulate and mount single molecules, such as DNAs, RNAs and proteins, into a nanogap junction and use the electric signals passing through the molecule to find out its sequence, structure or specific interactions such as antigen-antibody bindings. Our technology uniquely enables tight integration of nanofluidic channels with self-aligned transverse nanogap tunneling junctions on a chip for multiplexed delivery and detection of DNA/RNA/protein samples for point-of-care applications. In addition, the local electric field in the nanochannel is engineered to promote enrichment and guided delivery of biomolecules to the detection center where anchor molecules are present for highly specific sensing. The high sensitivity of single-molecule tunneling signals and local enrichment design of our technology can enable low-copy-number detection without amplification processing.