Interactions of polypyridyl cobalt complexes with DNA studied by rotating electrode methods

Abstract

The interaction of transition metal complexes Co(phen) 2 TATP 3+ , Co(phen) 3 3+ and Co(bpy) 3 3+ (where TATP ¼ 1,4,8,9-tetra-aza-trisphenylene, phen ¼ 1,10-phenanthroline, and bpy=2,2¢-bipyridine) with calf thymus DNA was investigated using the rotating ring-disk electrode technique. The values of the apparent diffusion coefficient and rate constant at the formal potential for reduction of these three polypyridyl cobalt complexes were found to decrease significantly in the presence of DNA as compared with that in the absence of DNA. The formal potentials at which the redox reaction takes place in the absence or presence of DNA were in the order of Co(phen) 2 TATP 3+/2+ > Co(phen) 3 3+/2+ > Co(bpy) 3 3+/2+ . The interaction between the complexes and DNA varied significantly, depending on the nature of ligands. The binding strength of these complexes to DNA was found in the order of Co(phen) 2 TATP 3+ > Co(phen) 3 3+ > Co(bpy) 3 3+ . The interaction modes of the polypyridyl cobalt complexes with DNA were discussed in line of electrochemical observations.

Voltammetric determination of 6-mercaptopurine using [Co(phen)3]3+/MWNT modified graphite electrode

“…[Co(phen) 3 ](ClO 4 ) 3 was prepared and purified according to the procedures reported previously [28][29]. Tris (where Tris is tris(hydroxy methyl) amino-methane) was purchased from Sigma Chemical Company.…”

Electrocatalytic activity of [Ru(bpy)3]2+ for hypoxanthine oxidation studied by rotating electrode methods

“…3 ] 3+ from the rotating disk electrode can be transferred onto the ring electrode and its adsorption is very weak on the rotating Pt surface [38]. The results provide a powerful basis for carrying out the electrocatalytic oxidation of Hx below.…”

Electroactive intercalators for DNA analysis on microchip electrophoresis

“…They were both employed as DNA groove binders and intercalators [51,52]. The ligand 1,10-phenantroline (phen) possesses three aromatic rings and when it is compared with other polypyridyl ligands in cobalt complexes, it results to be the most electrochemically reactive [53]. Ru(phen) 3 21 and Fe(phen) 3 21 showed an irreversible oxidation process at 11.2 and 11.0 V, respectively (Fig.…”