For The Research And Application Of Novel Fluorescent Probes In Cells Detected With The Life Of Metal Ions

The activity of life is an effect of different chemical reactions by lots of biological active substances, and metal ions is an important kind of them. Essential trace metal elements participate in almost all the physiological processes, for example, they play critical roles in maintaining the structure and realizing the normal function of protein, nucleic acid, peptides, incretion and other big biology molecule. Besides, some other metal elements such as heavy metal ions are toxic and harmful to organisms even at very low concentrations. So the detection of metal ions especially the detection in vivo and in situ is important to the research of biology, medicine and environment science.Current methods for detecting metal ions have already been developed, such as atomic absorption/ emission spectroscopy, high-performance liquid chromatography (HPLC), inductively coupled plasma mass spectrometry (ICPMS), electrochemistry, chemiluminescence (CL), and they display high sensitivity and selectivity and are usually used for quantitive analysis. However, these assays are not suitable for monitoring metal ions on line, and they can not describe the distributing and dynamic changes of the aim substances in cells. Compared with the above techniques, the fluorescent method is a powerful tool in cell biology because of its generally nondestructive character, high sensitivity and specificity. Searching for novel metal ions fluorescent molecular probes with high selectivity has attracted large attention of current analytical chemistry.As the development of confocal fluorescence imaging technique, the near-infrared region (NIR) fluorescent probes are more suitable for intracellular fluorescent imaging, because in this area there is low background fluorescence interference in biological systems. Besides, photoinduced electron transfer (PET) quenching mechanism have more sensitivity than other mechanisms, so PET fluorescent molecular probes are more attractive.We need to design and synthesize metal ions near-infrared region fluorescent probes, and study the property of the probes in chemical system, and then detect the concentration changes and the distribution of metal ions in cell on line according to confocal fluorescence imaging technology. This will be helpful to explore the function of metal ions in life activity and pathology of the shortness of metal ions and afford essential basis for biology and medicine study. Based on the photoinduced electron transfer (PET) quenching mechanism in designing new-typed near-infrared region fluorescent probes for trapping metal ions in cells, we have carried out two aspects of investigation:First, we designed and synthesized a new mercury (II) near-infrared region fluorescent probe 3,9-dithia-6-monoazaundecane-tricarbocyanine and characterized it by 1H-NMR, 13C-NMR and mass spectrometry. The reaction mechanism was studied. Excellent sensitivity and selectivity for mercuric ions are observed with this probe. Confocal microscopic imaging of Hg2+ within HepG2 cells and 5-day-old zebrafish reveals that the probe is cell-permeable.Second, we designed and synthesized a new near-infrared region fluorescent probe. The fluorescence spectrum of the probe showed wide excitation and narrow emission. Primary analytic experiment showed that it is selective to nickel ion.