Single nanopores as a model system to probe interfaces in aqueous and organic media

Nanopores with tunable geometry and electrochemical properties of the pore walls serve as a template to understand ionic and molecular transport at extreme confinement. Due to nanoconfinement, nanopores can exhibit ionic selectivity, i.e. the ability to transport only one type of ions, nonlinear current-voltage characteristics, and ion current switching behavior, among others. In the talk, I will present how ionic current through nanopores can be used to uncover properties of solid/liquid interfaces in aqueous and non-aqueous media. In the research we used single nanopores with opening as small as a few nanometers prepared in polymer as well as silicon nitride films. I will show how effective surface charge of the pore walls can be switched when the pore is in contact with multivalent ions and even salt solutions in some organic solvents. Finally, benefits of connecting nanopores in ionic circuits will be shown as well together with a design of ionic amplifiers.