Spectroscopic and voltammetric study on the binding of aluminium(III) to DNA.

Cyclic voltammetry (CV) and ultraviolet (UV) spectroscopy were used, for the first time, to study the interaction between aluminium(III) and calf thymus DNA under neutral pH conditions. Thus obtained data confirmed the existence of a relatively strong interaction between Al(III) and DNA. The binding site for aluminium(III) on DNA chains is not the bases, but the phosphate groups on the DNA backbones, the same as that for [Co(phen)3](3+/2+) that binds non-specifically and electrostatically to the deoxyribose phosphate backbone of DNA. When coexisting, Al(III) binds more favorably to DNA than [Co(phen)3](3+/2+), which implies the relatively strong binding of Al(III) to the phosphate backbone of DNA under neutral pH conditions. The nature of the binding of Al(III) to DNA is also discussed.