Irradiation of polymer foils with a single highly energetic heavy ion leads to a straight ion track. This damaged zone can chemically be etched up to a single nanochannel. When the etch is done from one side only, a conical nanochannel is obtained. The small aperture of it can be in the range of several nanometers, making it interesting for asymmetric ion transport in a liquid, which can be the core of a physical/chemical nanosensor device. In the present contribution, the formation of nanochannels, the chemical modification of the nanochannel walls, and its function as an electrochemical nanosensor are described. This is demonstrated with results from the author's lab in a collaboration with GSI Center for Heavy Ion Research. The examples with a variety of applications include nanochannel sensors for measuring temperature and pH value, e.g. [1], as well as highly sensitive and selective quantitative measurements of biomolecules, e.g. [2].

[1] M. Ali, P. Ramirez, S. Mafé, R. Neumann, W. Ensinger, A pH-tunable nanofluidic diode, ACS Nano, 3 (2009) 603-608

 [2] M. Ali, B. Schiedt, R. Neumann, W. Ensinger, Biosensing with functionalized single asymmetric polymer nanochannels, Macromolecular Bioscience 10 (2010) 28-32

Wolfgang Ensinger*, Darmstadt University of Technology, Germany

*presenting author