Nanopores emerged as the basis for preparation of sensors for molecules as well as model system to study interactions of water, ions and molecules at the nanoscale. My group prepares single pores in polymer and silicon nitride films with tunable opening diameter down to ~2 nm, controllable geometry, and chemical characteristics of the pore walls. I will present our results on building valves for water and molecules based on pores with hydrophobic walls. We showed that single hydrophobic nanopores could undergo reversible wetting and dewetting due to condensation and evaporation of water inside the pores. The wetting/dewetting process was observed as switching between conducting and non-conducting ionic states, and was regulated by the external electric field.
Being inspired by unique transport properties of biological channels in a cell membrane, we prepare polymer nanopores of similar transport properties to these of biochannels. I will summarize our efforts to create a synthetic analogue of biological voltage-gated channels.
I will also describe advantages of using high aspect ratio pores with undulating pore diameter in the detection of viruses. The ‘rough’ pores give information not only on the size of the passing object but also its shape and mechanical properties.