A bias across a thin membrane drives an ionic current through a single nanopore. A charged particle pulled through the pore blocks part of that current — bigger particles block more, and the dip's depth and duration fingerprint each event.
K⁺ (to cis −)Cl⁻ (to trans +)Analyte: small / medium / large (negatively charged)SiNₓ membrane
Next particle
Higher bias raises the open-pore current and pulls particles through faster (shorter dwell). Each dot in the scatter is one translocation event. Values are illustrative.