Flavonoids And Curcumin And Nucleic Acid Interaction And Its Analytical Application

Nucleic acids and proteins are the material base of all life. They are the carrier of genetic information and also are the determinative factor for species' continuation and evolution. They nearly relate to heredity, tumor, the effect of virus, and so on.The luminescent probes including fluorescence, chemiluminescence and resonance light scattering are the important means for the research and determination of both nucleic acids and proteins, so they have become the forward position and hot point in the area of life science. By using the fluorescence technique, this thesis penetrates the new probe of nucleic acids, and studies their interaction and luminescence mechanism.In the first section, we summarize recent developments of the probe for nucleic acids, and the recent investigation of vitamins detection.In the second section, the fluorescence enhancement of Morin-Y³⁺-CTAB-nucleic acids and its analysis application are studied. In Tris-HCl (pH=7.0) buffer, the fluorescence intensity of Morin-Y³⁺-CTAB system can be greatly enhanced by nucleic acids at 525nm and the enhanced intensity of fluorescence is in proportion to the concentration of nucleic acids in the range 5×10^-3-4μg/ml for fsDNA and 5×10^-3-1μg/ml for yRNA, the detection limits are 1.7 ng/ml for fsDNA, 1.5 ng/ml for yRNA, respectively. The synthetic samples were satisfactorily determined. The interaction mechanism is also studied. It is considered that CTAB and nucleic acids can bind with the complex of Morin-Y³⁺ through electrostatic attraction and form a large Morin-Y³⁺-CTAB- nucleic acids complex. At the same time, nucleic acids-CTAB system provides an optimum hydrophobic environment with low polarity and large viscosity for Morin-Y³⁺ complex which make the fluorescence intensity of the latter enhanced. In addition, the hydrophobic environment of nucleic acids-CTAB system can also prevent the collision between complex and water and decrease the energy loss of the Morin-Y³⁺-CTAB-nucleic acids system. Thus, the fluorescence quantum yield is improved and the fluorescence intensity of Morin-Y³⁺ system is significantly enhanced.