Study of the interaction of CTZAMB-Cu(II) with DNA and the determination of DNA

In this paper, the electrochemical behavior of the CTZAMB-Cu(II) complex with DNA has been investigated in potassium hydrogen-phthalate buffer solution (pH 2.5). In the absence of DNA, there was a sharp reduction peak in the single sweep polarogram due to the presence of CTZAMB-Cu(II), while in the presence of DNA this peak decreased in a quantitative fashion. This decrease in peak current is due to the formation of the CTZAMB-Cu(II)-DNA complex. Under the optimum conditions, the decrease of peak current is linear with DNA concentration in the range from 3.0 × 10−7 to 7.0 × 10−6 g ml−1, and the detection limit is 1.0 × 10−7 g ml−1. This new method exhibits a good recovery and sensitivity, which could be applied to the determination of DNA in real samples. The mechanism of the interaction of DNA and CTZAMB-Cu(II) is also discussed.