Study On Novel Fluorescent Probes For Determination Of The Nucleic Acids

The nucleic acids is the substantial base of biologic heredity, that is correlated with the natural and unnatural life activity, such as growth and pathological changes. Detecting and quantitating small amounts of nucleic acids is considerably important in many fields,such as biotechnology, pharmacodynamic and medical diagnostics. The quantificational analysis was the base of its configuration and function. Up to now, many methods have been developed to determine nucleic acids. The spectrophotometric procedures are commonly applied in many cases due to their good reliability, simplicity and reproducibility. The natural fluorescent intensities of nucleic acids are so weak that direct use of fluorescent emission to study their structure and biological properties is limited and that fluorescent probe is adopted to determine it. The fluorescent assay has been studied with good sensitivity, selectivity and simple operationIn this paper, four different drugs and their metal complexes were applied to determine nucleic acids. We probed into the condition that tetracycline, pefloxacin, emodin and myricetin interacted with nucleic acids, studied their mechanism, and application in synthetic samples was analysed. The research results are as follows:1. Based on the binding interaction of nucleic acids and the copper (II) - emodin (EM) complex, a fluorescent assay for nucleic acids was described. At pH = 5.6 the binding reaction was completed within 1 min at room temperature, and caused the decrease of fluorescence intensity at the wavelength of maximum emission of the complex, 434 nm. Under the optimal conditions, the calibration graphs were linear over the range of 0.08-1.2μg·mL-1 for ctDNA and 0.07-1.3μg·mL-1 for yeast RNA, respectively. The analytical results of synthetic samples were satisfactory, with the relative standard deviations of five determinations of 3.2-4.6% for 1.0×10-6μg·mL-1 ctDNA. The association constant of ctDNA with the complex was estimated, and the mechanism of the interaction between EM-Cu (II) and nucleic acids was discussed.2. The interaction of tetracycline (TC)-Zn (II) complex with DNA was studied by fluorescence and UV spectra method. Tetracycline could bind to calf thymus DNA with affinity...