The proteins contained in cell membranes, the so-called ion channels, recognise physical and chemical signals very selectively and transform these into measurable electrical signals. Potassium channels, as found for example in
 human cells as well as viruses, only allow potassium ions to enter, thereby playing an important role in the regulation of the blood glucose level as well as in the signal transmission between neurons. In the LOEWE research cluster iNAPO, biologists, chemist, physicist, material scientists, and electrical-technicians are working together to understand the structural and functional principles of these biological sensors and to imitate them. Working with the biological model, they want to build conductive nanosensors in solid materials which can then be used in analytics and biomedicine.  In medical diagnostics, for example, highly sensitive sensors could be used to register tumour markers or other substances in a drop of blood and to convert the concentration of such substances into an electrical Signal.