Fluorescence Determination Of DNA And Electrochemical Behaviors Of Based

Having the function of storing and transmitting information, DNA is the undertaker of genetic information and the basic of gene expression. The rapid detection of nucleic acid is absolutely necessary for the areas of environmental monitoring, food analysis, medical jurisprudence and so on. Developing exact way to detect sequence and concentration of DNA and developing micromation analysis apparatus are the tasks which are currently cared by analytical chemistry, molecule biology, oncology, clinic medicine and so on. Since discovering electrochemistry activity of nucleic acid, the research of electrochemical behavior of DNA and its internal groups has attracted great attention.Based on the above view, Cu(TSSB)₂²⁺ complex was synthesized in this thesis. The electrochemical and photochemical methods were used to study the interaction between DNA and this complex, and then to quantitatively determine DNA using photochemical trait of Cu(TSSB)₂²⁺ complex. In order to further discuss the special quality of purine groups, the nano-materials modified electrode, which has the special quality of enhancing selectivity and sensitivity, was used to determine the purine structural unit of DNA and oxidation product of damaged DNA. The thesis consisted of four chapters:(1) First of all, the research of DNA was simply discussed. Then preparation, classifying and application of modified electrode were reviewed in the chapter 1. Moreover, we presented the capability and application of nano-copper oxide. Finally, the research proposal was presented.(2) In chapter 2, the Cu(TSSB)₂²⁺ complex was synthesized, and the interaction between Cu(TSSB)₂²⁺ complex and DNA was discussed by using UV-Vis, fluorescence spectrophotometry and voltammetry. According to the ratio of the binding constants (k+/k2+) for binding of Cu(TSSB)2+ and Cu(TSSB)₂²⁺ complexes, and interaction between thermal-denatured DNA and Cu(TSSB)₂²⁺ complex, we could introduce that the main binding mode of Cu(TSSB)₂²⁺ complex with DNA was electrostatic binding. The fluorescence intensity of Cu(TSSB)₂²⁺ complex enhanced in the presence of DNA. Making use of this property, the Cu(TSSB)₂²⁺ complex was applied as a fluorescence probe to determine DNA.(3) In chapter 3, Copper oxide nanocrystals (nano-CuO) was prepared and was bound to cysteamine (CA) film which was covered glassy carbon electrode (GCE). The fabricated nano-CuO/CA/GCE sensor exhibited sensitive response to 8-OH-dG in 0.1 M PBS (pH 7.0) by cyclic voltammetry and differential pulse voltammetry. The nano-CuO/CA/GCE could be applied to detect 8-OH-dG in samples.(4) In Chapter 4, nano-copper oxide modified glassy carbon electrode (nano-copper oxide/GCE) was prepared by electrodeposition method. The fabricated electrode exhibited sensitive response to guanine and adenine by cyclic voltammetry and differential pulse voltammetry. The results indicated that the response signal of guanine and adenine was greatly enhanced at nano-copper oxide/GCE compared to bare electrode. The proposed method was used to simultaneous determine guanine and adenine.