Electrochimica Acta, Vol.53, No.16, 5169-5173, 2008
DNA-promoted electrochemical assembly of [Ru(bpy)(2)dpp](3+/2+) on the ITO electrode by introducing copper(II) ion
The electrochemical assembly of [Ru(bpy)(2)dpp](3+/2+) (where bpy = 2,2'-bipyridine, dpp = 2,3-bis (2-pyridyl) pyrazine) promoted by calf thymus DNA on an ITO electrode based on the introduction of copper(II) ion has been investigated. There exists a diffusion-controlled wave and two prewaves for the complex in the differential pulse voltammetric sweeping process. The formal potential of the high prewave shift ca. 0.530V negatively compared with that of the diffusion-controlled wave. Dpp ligand with two vacant chelating N sites in the complex can bite Cu2+ and the resultant heterometallic complex shows a weakened assembly in contrast to that of [Ru(bpy)(2)dpp](3+/2+) alone. Furthermore, double stranded DNA is able to accelerate the assembly of the ruthenium complex and heterometallic complex generated by chelating with Cu2+ by using the ITO surface, the prompted strength of the latter is far stronger than the former. Their assembled mechanism enhanced by DNA is proposed. (C) 2008 Elsevier Ltd. All rights reserved.