Abstract |
Properties of solid/liquid interface determine transport properties of nanosystems such as
nanopores. Inspiration to probe ionic and molecular transport at the nanoscale comes from nature
where ion channels in a cell membrane regulate transport of ions in and out of the cell.
Channels that are responsive to external stimuli including change of the transmembrane
potential, chemical or mechanical stress are the basis of all physiological processes of a living
organism. I will describe our efforts to prepare biomimetic nanopores with tunable geometry and
surface characteristics, which function as a rectifier, diode, and transistor for ions. These
system could also be considered as ionic equivalents of electronic devices. I will also present our
newest results on designing nanopores that are selective for one type of cation, mimicking the
behavior of biological potassium channels. Our potassium selective nanopores transport potassium
ions 100 times more efficiently than sodium ions. Finally, I will discuss unique properties of
solid/liquid interfaces in organic media. Experiments will be shown, which demonstrate that a
solvent can play an important role in the formation of effective surface potential.
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