Combinatorial microelectrochemistry: Development and evaluation of an electrochemical robotic system

An electrochemical robotic system using standard microtiter plates as reaction wells for potentiostatic and galvanostatic electrosynthesis and high-throughput electroanalysis was conceived and realized using stepmotor driven positioning stages in combination with a flexible software. Electrode bundles specifically adapted to the experimental needs are accurately positioned in the wells of a microtiter plate followed by the automatic performance of sequences of electrosynthetic or electroanalytical techniques. The system allows us to work under inert-gas atmosphere, in aqueous and organic solvents, and to add or remove solutions by means of integrated syringe pumps. A specifically developed script language permits the user to perform very complex experimental sequences in the different wells of the microtiter plate. The hardware and software features of the developed electrochemical robotic system, the design of suitable electrode arrangements for electrosynthesis and electroanalytical techniques, as well as the reproducibility in aqueous and organic electrolytes are described. The performance of the system is demonstrated by redox screening of a Ru-complex library and by electrosynthesis with in situ analysis of a compound library.