Pattern Recognition of microRNA Expression in Body Fluids using Nanopore Decoding at Sub-femtomolar Concentration

This paper describes nanopore decoding for microRNA (miRNA) expression patterns using DNA computing technology. miRNAs have shown promise as markers for cancer diagnosis due to their cancer type-specificity, and therefore simple strategies for miRNA-pattern recognition are required. We propose a system for pattern recognition of five types of miRNAs overexpressed in bile duct cancer (BDC). The information of miRNAs from BDC is encoded in diagnostic DNAs (dgDNAs) and decoded electrically by nanopore measurement. With this system, we succeeded in distinguishing miRNA expression patterns in the plasma of BDC patients using a label-free method and in real-time. Moreover, our dgDNA-miRNAs complexes can be captured by the nanopore at ultralow concentration, such as 0.1 fM. Such nanopore decoding with dgDNAs could be applied as a simple and early diagnostic tool for cancer in the future.