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DY: Dynamik und Statistische Physik

DY 24: Nonlinear stochastic systems

DY 24.2: Vortrag

Dienstag, 25. März 2003, 15:00–15:15, G\"OR/226

Preparation of ion current rectifying asymmetric nanopores — •Zuzanna Siwy¹, Andrzej Fulinski², Pavel Apel³, Dobri Dobrev¹, Reinhard Neumann¹, Reimar Spohr¹, and Christina Trautmann¹ — ¹GSI, Planckstr. 1, 64291 Darmstadt, Germany — ²Jagellonian University, Krakow, Poland — ³Flerov Laboratory of Nuclear Reactions, JINR, Russia

There has been a continuously growing interest in basic phenomena originating from restricted geometries. We have focused on studies of transport properties of single asymmetric nanopores prepared in polymer foils. To fabricate single nanopores, we employed the track-etching technique, which is based on the irradiation of the foils with single heavy ions of high kinetic energy, and subsequent controlled chemical etching of the latent ion tracks. The transport properties of asymmetric pores in polyethelene terephthalate (PET) and polyimide foils were examined by current-voltage characteristics and ion current time series. We show that the pores in both materials are cation selective and rectify the ion current with the preferential direction of the cation flow from the narrow entrance towards the wide opening of the pore. Nanopores in PET produce voltage-dependent ion current fluctuations, with the kinetics of openings and closings similar to voltage-gated ion channels in biological membranes. In contrast to this behaviour, the ion current through polyimide nanopores is stable in the entire examined range of voltages.