Studies Of Metal Complex Reacting With DNA By Electrochemical And Spectra Method

DNA is the basic genetic substance of creatures and a very important kind of biological molecule. It's connected with the growth, canceration and mutation of creatures, so it's helpful to understand the essence of life to study DNA from each aspect. The research about the mechanism of DNA with distinguishing molecules, especially DNA with medical molecules by electrochemical and spectral techniques is the leading field of bio-electrochemistry. The macro-information of the interaction can be obtained by electrochemical studies, and the spectral studies will be helpful to understand the mechanism of the interaction. The combination of the two techniques is very important to understand the mechanism. In this thesis, the mechanism of DNA with some kinds of metal complex was studied by electrochemical, UV-spectrophotometric and fluorescent method and was applied to the analysis. The main contents are listed as follows:(1) Alizarin complexone(ALC) is a ramification of anthraquinine and has been used in the studies of polarographic wave. In this paper, the mechanism of the interaction of ternary complex Ce(III)-ALC-F" and herring sperm DNA (hsDNA) is studied for the first time by electrochemical, fluorimetric and UV-spectrophotometric methods. The experiments indicate that Ce(III)-ALC-F"interacting with hsDNA in a binding mode of intercalation produces an electrochemically non-active complex, which results in a decrease of the peak current of Ce(III)-ALC-F . The Ip of Ce(III)-ALC-F"decreases linearly with DNA concentration from 0.5 to 5.5μg/mL, the detection limit is 0.05μg/mL, and so can be applied as an electrochemical probe to determine the concentration of DNA.(2) The mechanism of the interaction of Ca-ALC and herring sperm DNA (hsDNA) is studied by electrochemical, and UV-spectrophotometric methods. The experiments indicate that Ca-ALC interacting with hsDNA in a binding mode of intercalation produces an electrochemically non-active complex, which results in a decrease of the peak current of Ca-ALC. The Ip of Ca-ALC decreases linearly with DNA concentration from 0.1 to 3 μg/mL, and the detection limit is 0.01μ g/mL. This reaction can be complished within 2min at room temperature. Compared with some other methods, the procedure is simple and rapid and so canbe applied to determine the concentration of DNA.(3) The mechanism of the interaction of Pd( II )-5-Br-PADAP and herring sperm DNA (hsDNA) is studied by electrochemical, and UV-spectrophotometric methods. The experiments indicate that Pd( II )-5-Br-PADAP interacting with hsDNA in a binding mode of intercalation produces an electrochemically non-active complex, which results in a decrease of the peak current of Pd( II )-5-Br-PADAP. The Ip of Pd( II )-5-Br-PADAP decreases linearly with DNA concentration from 0.3 to 3 μ g/mL, and the detection limit is 0.02 μ g/mL. This complex can be applied as a distinguishing molecule for DNA.