Highly sensitive heavy metal analysis on platinum- and gold-ultramicroelectrode arrays

The use of platinum- and gold-ultramicroelectrode arrays for heavy metal analysis is described. The noble metal microelectrodes are structured with standard silicon technologies. The geometry of the electrode array is varied and optimized in regard to the microelectrode characteristic. Mercury film formation and -dissolution on platinum microelectrode arrays is characterized and compared with iridium electrodes of the same geometry. Gold microelectrode arrays are shown to be useful for mercury detection. The repeated use of the sensors has been studied. Optimizing the electrode geometry and the stripping procedure results in detection limits down to the ng/L range.