DNA-promoted electrochemical assembly of [Ru(bpy){sub}2dpp]{sup}(3+/2+) on the ITO electrode by introducing copper(II) ion

摘要

The electrochemical assembly of [Ru(bpy){sub}2dpp]{sup}(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. 0.530 V negatively compared with that of the diffusion-controlled wave. Dpp ligand with two vacant chelating N sites in the complex can bite CU{sup}(2+) and the resultant heterometallic complex shows a weakened assembly in contrast to that of [Ru(bpy){sub}2dpp]{sup}(3+/2+) alone. Furthermore, double stranded DNA is able to accelerate the assembly of the ruthenium complex and heterometallic complex generated by chelating with CU{sup}(2+) 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.