Development of test chips for electrochemical analysis

Abstract:
There are numerous voltammetric and amperometric analysis methods to determine various parameters of an analyte solution. Depending on the electrochemical measuring principle, the number, positioning, material and area of the electrodes used are of particular importance. Noble metals such as gold or platinum are widely used as working electrodes, while a Ag/AgCl/KCl-based electrode is typically used as the reference electrode. In practice, conventional electrodes and electrode arrangements have considerable disadvantages. On the one hand, the costs of materials are high, because precious metal sheets or wires are widely used as electrodes. On the other hand, wetting of the electrodes needs to be ensured, which means that 20 ml or more of analyte is required, depending on the measuring arrangement. The aim of this work was therefore to manufacture and arrange accurate electrodes with the lowest amount of used precious metals as possible in order to enable typical electrochemical measuring methods with a reliable and reproducible setup. The goal was not only to minimize the amount of precious metals for electrodes, but also to reduce the amount of analyte to one drop, i.e. to about 30 mul. At the same time, the resulting measuring component should be easy to handle and to use, both in aqueous media and in organic solvents.