How exactly does the nanopore platform detect microRNA?

The MinION/Yenos detection process works in three steps. First, miRNA molecules extracted from the urine sample are tagged with Yenos's osmium metalorganic probes — these bulky chemical groups attach to specific nucleobases in the miRNA sequence, creating a distinctive molecular 'handle.' Second, the tagged miRNA solution is loaded onto the MinION flow cell. The applied voltage (approximately 180 mV) drives the osmium-tagged miRNA strands through the nanopores one molecule at a time. Third, when each tagged miRNA threads through a nanopore, it produces a characteristic current blockage event — a specific dip in the 180 pA baseline current. The depth, duration, and shape of each blockage event identifies the molecule as a specific miRNA and counts it. The total count per unit time is proportional to the concentration.