Application Of Gatifloxacin-Terbium Complex In The Analysis Of Life

Mutation, deletion or change in concentration of DNA base will result in the generation of human diseases. Aberrant ATP levels have been associated with particular diseases such as angiocardiopathy and so on. So, the detection of DNA and ATP plays a critical role in disease diagnosis, prevention and biomedical research. As a fluorescence probe, rare earth ion compounds have narrow spectral width, stable chemical structure, long fluorescence lifetime, large stock shift, and they are friendly to biological molecules. So they are widely used in detection of biological molecules and drug molecules. The present paper used the gatifloxacin-terbium (Ⅲ) complex as a fluorescence probe to detect DNA and ATP respectively, based on DNA and ATP increasing the fluorescence intensity of the system. Besides, the paper discusses the luminescence mechanism of the systems through fluorescence spectra, ultraviolet absorption spectra and the analysis of relationship among terbium (Ⅲ), gatifloxacin and water molecules.The main contents are as follows:1. The structure of DNA and ATP as well as the significance of their detections were simply introduced. The current detection methods were described in detail. The rare earth ion compounds, their features as a fluorescence probe and their application in life analysis were also introduced.2. The new lanthanide ions-gatifloxacin fluorescence systems of GFLX-Tb3+-ctDNA was established and applied to the determination of ctDNA. ctDNA can effectively increase the fluorescence intensity of the GFLX-Tb3+system, thus the new fluorescence systems of GFLX-Tb3+-ctDNA was established. The enhanced fluorescence intensity and DNA concentration showed a good linear relationship in a certain DNA concentration range. So we can achieve the detection and quantitation of DNA. Under optimal conditions, an excellent liner relationship between△F and the calf thymus DNA concentration was obtained in the range from5.8×10-7g mL-1to2.0×10-5g mL-1. The detection limit of the assay was determined to2.2×10-7g mL-1. This chapter also detected some interfering ions and materials, as well as DNA in synthetic water sample, all recoveries were in the range of95%～102%. In addition, this chapter also discussed the luminescence mechanism of the systems. This method didn’t need any modification, the detection process is simple, fast and had a good reproducibility.3. The new lanthanide ions-gatifloxacin fluorescence systems of GFLX-Tb3+-ATP was established and applied to the determination of ATP. ATP can effectively increase the fluorescence intensity of the system. Under optimal conditions, an excellent liner relationship between△F and ATP concentration was obtained in the range from2.1×10-6mol L-1to2.4×10-5mol L-1. The detection limit of the assay was determined to1.9×10-6mol L-1. The interference of some common coexisting substances such as amino acids, metal ions on the system was also determinated. We detected the commercially available ATP injection, and the recovery and precision of the detection were satisfactory. In addition, this chapter used fluorescence spectroscopy and UV absorption as well as the analysis of relationship among terbium (III), gatifloxacin and water molecules to discuss the luminescence mechanism of the systems.4. A DNA fluorescence assay based on rolling circle amplification and circle fluorescence amplification strategy by exonuclease Ⅲ (Exo Ⅲ) was attempt to establish. In the absence of target DNA, complementary DNA showed the status of the single-stranded, RCA reaction was initiated by addition of the circular template, polymerase, ligase and dNTP. After addition the probe DNA and inserted dye SYBR Green I, the system showed a strong fluorescence signal. When the system existed in the target DNA, complementary DNA and target DNA hybridized to form a duplex with a recessed3’terminus that can be digested by Exo Ⅲ, the target DNA will then be released to bind another complementary DNA to undergo a new cleavage reaction. The cleaved complementary DNA can not initiate rolling circle amplification. In this method, each cleavage reaction corresponded to one RCA product which can be inserted into a large number of SYBR Green I. The method did not require fluorescent labeling of DNA; the whole reaction process and testing process were in a homogeneous solution and did not need separation. We conducted a preliminary study of the experiment and optimized the time of the inactivation of Exo Ⅲ and the concentration of primer.