通过改变探针的反应速率以实现在纯水溶液中检测氟离子的研究

发布时间：2019-06-15 12:07

【摘要】：目的:作为半径最小的阴离子,氟离子在很多方面发挥着重大作用,如在医学方面,氟离子摄入不足会引发龋齿和骨质疏松,而摄入过量又会引发氟斑牙,氟骨病。另外慢性长期接触低剂量的氟离子会导致胃和肾脏疾病,尿石病甚至死亡。因此识别、监测氟离子具有重要的意义。荧光探针不仅具有选择性好、灵敏度高等优点,同时又能应用于生命体系。目前大多数已报道的氟离子荧光探针仅能在有机溶剂体系中或是大比例的有机溶剂中检测四丁基氟化铵(TBAF),而能够用于水中氟化钠检测的探针多数需要加入一定比例的有机溶剂,或是加入表面活性剂如十六烷基三甲基溴化铵(CTAB)以提高响应速率。能够应用于纯水体系中的探针少有报道。本课题的研究目的是探讨纯水体系中氟离子荧光探针对氟化钠的响应速率与探针结构的关系,并进一步发现能够应用于纯水溶液体系,响应迅速的氟离子荧光探针。方法:1.设计合成了两个系列的氟离子荧光探针,系列一以6-羟基苯并噻唑为母核,以叔丁基二甲基硅醚(TBDMS)保护6位羟基作为氟离子识别位点,母核的2位通过酰胺键连接糖基(化合物101),甲基(化合物102),苄基(化合物103);系列二以4-三氮唑基-7-羟基香豆素为母核,以叔丁基二苯基硅醚(TBDPS)保护7位羟基作为氟离子识别位点,三氮唑基上通过酰胺键引入糖基(化合物201),甲基(化合物202),对甲氧基苄基(化合物203)。2.分别测定浓度为10μM的各个探针在不同氟化钠浓度(200μM,500μM,1000μM)下的准一级速率常数,进而求得每个探针与氟离子(氟化钠)的二级反应速率常数。3.通过比较二级反应速率常数,修饰探针结构。在系列二的三氮唑基上引入聚乙二醇单甲醚(分子量:1000),得到新的探针,化合物204,测定其二级反应速率常数,并且研究了新探针对氟离子的灵敏度,选择性,以及细胞毒性和细胞成像。结果:1.首先得到了两个系列共六个化合物,其结构新颖,均是未见报道的化合物,经核磁共振氢谱,碳谱和高分辨质谱(ESI)确证了结构。2.测定了以上六个探针与氟离子反应的二级反应速率常数,系列一3个探针的二级反应速率常数关系为:化合物101化合物102化合物103;系列二3个探针的二级反应速率常数的关系为:化合物201化合物202化合物203。3.合成了新探针化合物204,经核磁共振氢谱,碳谱和质谱(MALDI)确证结构。该探针的二级反应速率常数明显大于化合物101和化合物201,对氟离子的检测限为0.34 mg L-1,并且对氟离子的选择性明显优于其他阴离子。以香豆素120为参比,化合物204的荧光量子产率为0.318。细胞毒性结果表明,该探针在实验浓度下对细胞无明显毒性。MB-231细胞经20μM氟化钠培养后,再用10μM化合物204处理后,可显示出明亮荧光。结论:本文先是设计合成了两个系列六个氟离子荧光探针,经二级反应速率常数对比得知,该类探针对氟离子的响应速度取决于探针的亲水性,亲水性越高,响应速度越快。然后以此结论为指导,设计合成了一个反应速率更高的氟离子荧光探针——化合物204,该探针对氟离子的检测限明显低于世界卫生组织对饮用水中氟离子含量上限的规定(1.5 mg L-1),并且对氟离子的选择性明显优于其他阴离子。细胞实验证明,化合物204对细胞无毒,且可用于检测细胞内氟离子。
[Abstract]:Objective: As the least-radius anion, fluoride ion plays a significant role in many aspects, such as the lack of fluoride ion in medicine, dental caries and osteoporosis. In addition, chronic long-term exposure to low-dose fluoride ions can lead to stomach and kidney diseases, urolithiasis and even death. Therefore, it is of great significance to identify and monitor the fluoride ion. The fluorescent probe not only has the advantages of good selectivity, high sensitivity and the like, but also can be applied to the life system. At present, most of the reported fluoroionic fluorescent probes can only be used for the detection of tetrabutyl fluoride (TBAF) in an organic solvent system or in a large proportion of organic solvents, and most of the probes that can be used in the detection of sodium fluoride in water need to be added with a certain proportion of organic solvent, Or a surfactant such as cetyl trimethylammonium bromide (CTAB) is added to increase the response rate. The probe which can be applied to the pure water system is rare to report. The purpose of this study is to study the relationship between the response rate and the probe structure of the fluoride ion fluorescent probe in the pure water system. Method:1. two series of fluorine ion fluorescent probes are designed and synthesized, a series of 6-hydroxybenzene is used as a mother core, a 6-position hydroxyl group is protected by a t-butyl dimethyl silicon ether (TBDMS) as a fluorine ion recognition site, and the 2-position of the mother nucleus is connected to the glycosyl (compound 101) through a melamine linkage, a methyl (compound 102), a phenyl group (compound 103), a series of 2-4-triaza-base-7-hydroxycoumarin as a mother core, a 7-position hydroxyl group is protected by a t-butyl diphenyl silicon ether (TBDPS) as a fluorine ion recognition site, a sugar group (compound 201) is introduced through a melamine bond on the triazine base, Methyl (compound 202), p-methoxyphenyl (compound 203). The quasi-primary rate constants of each probe with a concentration of 10. m u.M at different concentrations of sodium fluoride (200. mu.M,500. mu.M,1000. mu.M) were measured, respectively, and the second-order reaction rate constant of each probe and fluoride ion (sodium fluoride) was determined. The structure of the probe is modified by comparing the secondary reaction rate constant. Polyethylene glycol monomethyl ether (molecular weight:1000) was introduced on the triazine base of the series 2, a new probe was obtained, the compound 204 was obtained, the second-order reaction rate constant was determined, and the sensitivity, the selectivity, and the cytotoxicity and the cell imaging of the new probe to the fluorine ion were studied. Results:1. The two series of six compounds were obtained, and their structure was novel, all of which were not reported, and the structure was confirmed by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and high resolution mass spectrometry (ESI). The two-stage reaction rate constant of the above six probes and the fluorine ion is determined, and the second-order reaction rate constant of the series of three probes is as follows: compound 101 compound 102 compound 103; the relationship between the two-stage reaction rate constant of the series of two three probes is as follows: Compound 201 compound 202 compound 203.3. A new probe compound 204 was synthesized and the structure was confirmed by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrometry (MALDI). The second-order reaction rate constant of the probe is obviously higher than that of the compound 101 and the compound 201, the detection limit of the fluorine ions is 0.34 mg L-1, and the selectivity of the fluorine ions is obviously superior to other anions. The fluorescence quantum yield of compound 204 was 0.318, based on coumarin 120. The cytotoxicity of the probe showed no significant toxicity to the cells at the experimental concentration. The MB-231 cells were incubated with 20.mu. M sodium fluoride and then treated with 10.mu. M of compound 204 to show bright fluorescence. The response speed of the probe to the fluoride ion is dependent on the hydrophilicity of the probe, the higher the hydrophilicity and the faster the response speed. Based on this conclusion, the fluorine ion fluorescent probe _ compound 204 with higher reaction rate is designed and synthesized, and the detection limit of the probe to the fluoride ion is obviously lower than that of the World Health Organization (1.5 mg L-1) for the upper limit of the fluorine ion content in the drinking water. And the selectivity of the fluorine ions is obviously superior to other anions. Cell experiments demonstrate that compound 204 is non-toxic to cells and can be used to detect intracellular fluoride ions.
【学位授予单位】：天津医科大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R123.1

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