A solid-state nanopore can be used to sense DNA (or other macromolecules) by monitoring ion-current changes that result from translocation of the molecule through the pore. When transiting a nanopore, the highly negatively charged DNA interacts with a nanopore both electrically and hydrodynamically, causing a current blockage or a current enhancement at different ion concentrations. This effect was previously characterized using a phenomenological model that can be considered as the limit of the electro-hydrodynamics model presented here. We show theoretically that the effect of surface charge of a nanopore (or electro-osmotic effect) can be equivalently treated as modifications of electrophoretic mobilities of ions in the pore, providing an improved physical understanding of the current blockage (or enhancement).
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