The flavoprotein dodecin from the halophilic organism Halobacterium salinarum binds not only native but also artificial flavins with high affinities in their oxidized state. Reduction of the flavins induces the dissociation of the holocomplex into apododecin and free flavin. Based on these unique binding characteristics, a molecular crane shall be developed that is able to pick up and to release molecular objects through a switch of the electric potential. For this purpose, a single flavin has to be linked to the conductive tip of an atomic force microscope via a molecular wire-like subunit (flavin molecular wire AFM tip/electrode). On the basis of such an electrochemically switchable molecular crane, it will be possible to bind and release single molecules of dodecin apoprotein or even larger molecular assemblies attached to apododecin serving as molecular junction. While the construction of a molecular crane for the transport of single molecules is the main goal, the successful realization of this project fundamentally depends on the synthesis and characterization of molecular wire-like subunits, which can be used to attach redox-active proteins to surfaces in an electrochemically switchable state. Thus, functionalized single-walled carbon nanotubes or organic p-electron systems will be examined with respect to their ability to serve as molecular wire. Surface modification protocols have to be developed and modified surfaces will be investigated by a combination of atomic force microscopy, surface plasmon resonance spectroscopy, and electrochemical methods. The results of these studies will be of general interest for the construction of molecular switches, devices, and transport systems, and for the development of amperometric biosensors and biofuel cells.