A simple approach for fabrication of microring electrodes

Herein we describe a simple approach for fabrication of microring electrodes by electroless plating a thin layer of gold on polycarbonate (PC) rods. First, the PC rod was exposed to UV light to generate carboxyl groups on the surface. After amination of the surface carboxyl groups by ethylenediamine, the rod was sequentially immersed in HAuCl4 and NaBH4 solutions to form a layer of gold nanoparticles. These gold nanoparticles then functioned as the catalytically active centers for electroless plating thin gold film on the PC rod surface. Finally, the rod surface was thoroughly covered by an insulating glue and fresh microring surface could be obtained easily by laterally cutting with a knife. The electrochemical behavior of thus prepared microring electrodes were characterized by cyclic voltammetry in hydroxymethylferrocene and H2SO4. The whole fabrication process is simple and economic, which can be carried out in ordinary laboratories. In addition, the results of electrocatalytic oxygen reduction demonstrated that the proposed microelectrode could be used as an alternative electrode materials for electrocatalysis and electroanalysis.