Design, Synthesis And Biological Application Of Novel Reactive Fluorescence Probes For Detection Of Iodide In

The iodide ions play an important role in maintaining and regulating the stabilityof the intracellular environment. Many studies have shown that iodine is important tomaintaining the energy metabolism and normal thyroid function, regulation of cellmetabolism, nerve muscle development and growth, and so on. Either deficiency orabundance of iodide can cause harm to the body and lead to relevant thyroid diseases,such as goiter, hypothyroidism, hyperthyroidism, and so on. Therefore, thequantitative detection of the change of iodine ion and dynamic tracking can provideabundant physiological and pathological information for clinical medicine.In recent years, many traditional detection techniques have been developed foriodide, such as the traditional atomic absorption spectrometry, and capillaryelectrophoresis, gas chromatography-mass spectrometry (GC-MS) and inductivelycoupled plasma mass spectrometry (ICP-MS), However, many of these methods arecomplex, high cost, time consuming and difficult to realize online real-timemonitoring. Fluorimetric method is widely used in various fields for it is easy tooperate, quick response, high sensitivity and selectivity. The near-infraredfluorescence molecular probe is often used in laser-scanning confocal microscopy invirtue of less cell photodamage, low background and deeper penetration of tissue．Near infrared fluorescent molecular probes are commonly used in a variety of activesubstances the physiologic substances in yeast cells. In vivo acheived real-timedynamic imaging in situ, so that the physiologic substances in cells can be visualizing.Near infrared fluorescent molecular probes are widely used in the field of life sciences,medicine and so on.This thesis is based on that the small molecules fluorescence probeHCy-OMe-Br and iodine ion can specificity reaction and from the change of thefluorescence intensity of the probe, it is possible to detect the iodine ion specific inhigh selectivity and high sensitivity. And the probe HCy-OMe-Br can beensuccessfully used in iodine ion detection in cells by confocal microscopy imaging,realize real-time observation of iodine ion. The main work of the thesis could be summarized as follows:First, we design a novel reactive fluorescent molecular probes HCy–OMe-Br,due to the probe contains two bromine atoms, the heavy atom effect of bromine andthe lower the conjugation extent of the molecular chain together contributed tofluorescence quenching. Based on D-π-A refactoring reaction principle, when theprobe attack by iodine, double bromine in probe trans eliminate, π system cut byBromine will restore with a double bond bridging D-π-A molecule (HCy-OMe).Electron-withdrawing groups in the molecular structure of methyl indole salt(A) andelectron-donating groups benzene methyl ether (D) have strong intramolecular chargetransfer, the absorption and emission spectrum red shift (λex/λem=480nm/680nm),and the fluorescence enhanced significantly.Second, HCy-OMe-Br probe simplifies the identification process of iodide, theiodide ion can be detected rapidly with the advantage of high selectivity, highsensitivity; There is a good linear relationship between fluorescence intensity and theiodide ion concentration, the linear range0.05to300μM, the linear correlationcoefficient of0.9934, the limit of detection is8.87nM, indicating that the probe canbe quantitatively detected within a certain range of concentrations of iodide ion; AndpH in the6.8~8.2range has little effect on the probe, fluorescence intensity is stable;The probe may be used in biological systems for it has good selectivity in thebiological system, common anions and metal ions did not interfere; Kineticexperiments show that the probe has good stability, ensure that the fluorescencemethod is reliability.Third, the novel probe HCy-OMe-Br emitted in the near-infrared region and theStokes shift reaches200nm. The probe has many advantages such as goodbiocompatibility, less background fluorescence interference in biological samples andlow cytotoxicity; Probe successfully used for iodide ion imaging analysis in HepG2cells.