关键词: DNA, 稀土金属离子, 循环伏安法, 光谱法

Abstract: The interaction between rare earth ions(e.g.Eu 3+ ,Ce 3+ ,Er 3+ ,Sm 3+ ,Tb 3+ ,La 3+ and Nd 3+ ) and DNA had been investigated by using Cyclic Voltammetry, Ultraviolet and Raman Spectroscopy. After the adding of Ce 3+ ion to DNA solution, the cathodic peak current of Ce 3+ ion reduction was found to decrease obviously, and the anodic peak current to decrease even more significantly. Differential UV spectra of Ce 3+ ion depicted hyperchromic effect after the reaction of these two species and a new peak of 272 nm was found. Differential UV spectra of DNA also showed the hyperchromic effect. The peak of 814 cm -1 disappeared in the Raman spectra of DNA. All of above results may be interpreted as the cleavage effect of cerium ion on DNA. Similar effect were observed between Eu 3+ ion and DNA, but less significant than those observed in Ce 3+ -DNA system. Probably due to the electrostatic interaction between Eu 3+ and DNA and the stack effect of the base in DNA. Peak current decreasing and hyperchromic effect were also observed in cases of reaction of DNA with Er 3+ ,Sm 3+ ,Tb 3+ ,La 3+ and Nd 3+ , but all weaker than in Ce 3+ -DNA system. The cleavage effect of Ce 3+ on the phosphodiest linkage in DNA may be useful in employing the Ce 3+ ion as the “Molecular scission” for catalytically hydrolytic cleavage of DNA.

Key words: DNA, Rare earth ions, Cyclic voltammetry, UV and Raman spectroscopy