The Research Of Novel Metal Ion Adsorbents And Neurotransmitter Chemicals Fluorescent Probes

This thesis can be divided into two parts:part one is the preparation of functional adsorbent for the solid phase extraction of metal ions; Part two is the design and synthesis of neurotransmitter chemicals fluorescent probes for the detection of hydrogen sulfide and cysteine respectively.1. Higher sensitivity and accuracy of the trace metal ion determination were required in the development of modern science and technology. Further research of both determination and sample pre-treatment methods need to be conducted in the achievement of higher sensitivity and accuracy. As one of important sample pre-treatment methods, the solid phase extraction, which is applied for the enrichment and separation of trace metal ions in the various complex samples, has increasingly attracted strong interest of scientists. This part dedicated to the synthesis of novel metal ion adsorbent, which will be applied to solid phase extract trace metal ions in the various real samples, and the detail studies on the adsorption process of metal ions.1.1The polycondensation product of thiourea and diethylenetriamine was chemically grafted on the surface of silica modified3-(2,3-epoxy propoxy) propyl trimethoxy silane. A solid phase extractor (SG-DETA-TU) containing functional group-thiourea was preparated successfully. The extraction of heavy metal ion Hg(Ⅱ) from acidic aqueous under various experimental conditions was studied. Combined with solid phase extraction technology and inductively coupled plasma-atomic emission spectroscopy (ICP-AES), a new method of SG-DETA-TU for enrichment and separation of trace mercury in solution was established, and applied to extract trace Hg(II) in various environmental and biological samples.1.2After the characterizine of silica sorbents chemically immobilied ionic liquid1-(3-methyl thiourea propyl) imidazolium chloride (MTU-PIm-SG) with’HNMR, FT-IR, element analyzer, surface area and pore size analyzer, the selective adsorption of IIB metal ions Hg (II) from HCl solution was studied and conditions for adsorption and desorption was optimized. The stability of MTU-PIm-SG were investigated with multiple adsorption-desorption cycles and the kinetic and thermodynamic equilibrium of extraction process were discussed. 2. The hydrogen sulfide, besides nitric oxide and carbon monoxide, is an important neurotransmitter molecule in the cells and vivo, which plays a significant role in many physiological and pathological processes. In mammals, hydrogen sulfide is obtained from the cysteine and the similar chemicals through the biosynthetic progress of enzymatic reaction.The thiol molecules, such as cysteine, homocysteine and glutathione also play a very important role in the regulation of cell growth process and the abnormality of its concentration is relating to a series of diseases. Therefore, the qualitative and quantitative detection of these neurotransmitter molecules is significant and helpful for the in-depth research of their conduction mechanism and physiological effect in vivo. As an important method of fluorescence detection, fluorescent probe, because of its high sensitivity, low detection limit, simple preparation, real-time imaging, especially of its non-destruction for specific cells and tissues of organisms etc., is widely used in biological detection areas. For this reason, two novel fluorescent probe molecules were designed and synthesized in this part and used to selectively detect hydrogen sulfide and cysteine in HeLa cells, respectively.2.1The ratio fluorescent probe1of hydrogen sulfide was synthesized based on the mechanism of excited-state intramolecular proton transfer (ESIPT) and1,6-intramolecular elimination. The molecular structure and reaction pathway were confirmed by1HNMR,13CNMR, HPLC and ESI-MS, and the response mechanism of the probe1to hydrogen sulfide was verified by HPLC and ESI-MS. Furthermore, the sensitivity, selectivity, the applicable range of pH and response kinetics of probe1were studied. The probe1was applied to the fluorescence imaging detection of hydrogen sulfide molecules within HeLa cells after its toxicity was investigated.2.2The turn-on fluorescent probe2of cysteine was synthesized based on the mechanism of photoinduced electron transfer (PET) and intramolecular substitution reaction. The molecular structure and reaction pathway were confirmed by1HNMR,13CNMR, HPLC and ESI-MS, and the response mechanism of the probe2to cysteine was verified by HPLC and1HNMR. Furthermore, the sensitivity, selectivity, the applicable range of pH and response kinetics of probe2were studied.The probe2was applied to the fluorescence imaging detection of cysteine molecules within HeLa cells after its toxicity was investigated.