Electrochemical micro analysis system for heavy metal ions

A micro analysis system for heavy metal ions was fabricated. It consists of a double-junction reference electrode module and a working electrode module with micro electrode arrays. The Ag/AgCl element in the reference electrode module features a structure with multiple pinholes and AgCl layers grown from there. The reference electrode module could maintain an expected potential for longer than 40 h with a small amount of AgCl. Microelectrode arrays used for the working electrode exhibited characteristic sigmoidal cyclic voltammograms. Pb/sup 2+/ ions were detected as a model analyze to test the operation of the micro system. Anodic stripping voltammetry was conducted with mercury or bismuth micro electrode arrays. A linear relationship was observed between the peak current and Pb/sup 2+/ concentration for concentrations between 50 nM and 500 nM.