[Studies on the interaction of metalic complex and DNA by the spectral methods]

The interaction of [Cu(A)2]2+ (A = phen, bpy, en) complex ion and ct-DNA was investigated by using absorption spectra and fluorescence spectra. Based on the measurement of A260 in the different pH mediums, the alkaline denaturation curves of DNA in the absence and in the presence of [Cu(phen)2]2+ complex ion were obtained. The result showed that the alkaline denaturation for [Cu(phen)2]2+ complex ion occured at a higher pH than that for DNA alone. The absorption of EB-DNA system in the presence of [Cu(phen)2]2+ showed that [Cu(phen)2]2+ could partly sustain the place of EB. The result of fluorescence spectra suggested that the [Cu(phen)2]2+ complex ion could make the fluorescence intensity of EB-DNA system to decreased sharply. The effect of [Fe(CN)6]4- on the emission of [Cu(phen)2]2+ and [Cu(phen)2](2+) -DNA system was studied. All the experimental results indicated that the intercalative binding mode was the major mode for the interaction of [Cu(phen)2]2+ complex ion and DNA, and the size of ligands can effect the binding of complexes to DNA.