Microelectrodes modification through the reduction of aryl diazonium and their use in scanning electrochemical microscopy (SECM)

This work is devoted to the study of the electrochemical grafting of nitrophenyl groups onto platinum ultramicroelectrode (LIME). The grafting was made using the electrochemical reduction of nitrophenyldiazonium. Our results demonstrate the possibility to reduce the diazonium onto Pt UME. As consequence the electrochemical reduction leads to the attachment of nitrophenyl groups onto the UME surface. Following that, the modified UME was characterized using electrochemical techniques. In addition, the electrochemical response of the modified UME in the presence of reversible redox couple, ferrocene, has been studied. The main remark is that the steady state current observed at the UME is not affected by the presence of the nitrophenyl layers. Finally, from this last point we demonstrate the possibility to achieve scanning electrochemical microscopy (SECM) using modified platinum UME. (C) 2009 Elsevier B.V. All rights reserved.