There is provided a method for sensing the translocation of a molecule through a nanopore. In the method, there is directed to an inlet of a nanopore a molecule that is disposed in a first ionic solution of a first ionic concentration. The molecule is caused to translocate through the nanopore from the inlet of the nanopore to an outlet of the nanopore and into a second ionic solution of a second ionic concentration that is different than the first ionic concentration. An electrical potential, local to that ionic solution, of the first and second ionic solutions, which has a lower ionic concentration, is measured while the molecule is caused to translocate through the nanopore.