【作者】 李广全；

【导师】 李国文；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2009， 博士

【摘要】 糖是生物体内能量的传递物,是维持细胞生存的关键。如果糖的传递被破坏,则直接导致某些疾病如肾性糖尿、纤维囊肿、糖尿病甚至于癌症等各种疾病,严重影响着人们的身心健康。目前,控制糖尿病面临的主要挑战之一是制备能连续跟踪血糖浓度、可置入体内的器件,以便及时反馈人体血糖的浓度,为糖尿病的及时诊断、治疗提供准确的信息。化学传感器在这方面具有独特的功效,有些公司已经进行尝试,如药物传感器。众所周知,硼酸可以和含二醇化合物形成可逆硼酸酯,制备连续监测糖浓度的化学监测器;磷脂或表面活性剂在水溶液中可以形成囊泡,其中双亲分子的亲酯链构成亲酯区,亲水基团形成亲水区,囊泡的双分子层结构可以作为细胞膜的模型和药物载体。为了研发连续跟踪血糖浓度、可置入体内的化学传感器,我们通过在双亲分子上引入荧光发色团和可识别糖的硼酸功能基团,成功地实现上述目的。本文设计、合成了三种含有苯硼酸识别基团和喹啉或萘荧光读出基团的新型双亲化合物,并用核磁和元素分析等手段证明了三种双亲化合物的结构和组成。三种双亲化合物在选择性溶液中均可以形成球状的囊泡。详细讨论了以喹啉为生色基的两种双亲化合物形成囊泡后对糖检测的结果,并着重分析了囊泡传感器和小分子化学传感器的差异,进一步证明了囊泡传感器的优越性能。之后我们讨论了以萘为生色基的双亲化合物形成囊泡传感器对三种不同糖的检测结果,证明了PET效应对糖检测的影响。随着对DNMPBA囊泡体系认识的深入,同样是该分子的囊泡体系,在同时满足:1、糖类物质存在,2、用氮气排除溶液中的少量溶解的氧气,体系中萘的单线态发射峰发生微小变化,而在408nm处萘的激基缔合物的发射峰却出现了,随着单糖的量的增加,激基缔合物的发射峰也明显的增强。我们利用激基缔合物发射峰的强度与单线态发射峰的强度的比值变化作为检测糖的依据,得到了一种全新的高灵敏的检测方法。通过研究证明包含识别基团的双亲分子形成的囊泡传感器,不但可以解决血糖检测过程的连续性问题,还有可能制备出与血液长期接触的可植入式装置。使得对糖尿病患者血糖浓度及时跟踪检测成为可能。更多还原

【Abstract】 Saccharides are nature’s conveyors of energy and therefore essential for cell survival. The breakdown of glucose transport has been correlated with certain diseases: renal glycosuria, cystic fibrosis, diabetes, and human cancer, seriously affected our normal life. At present, One of the major challenges in the management of diabetes is the monitoring of glucose concentration, the device can be placed in the body, so that the accurate information will be provided . Chemsensors do have a unique effectiveness. Such a concept has already been put into test by companies such as sensors for medicine. It’s well known that boric acid and diol compounds can form a reversible Boric acid resin to Prepare a chemical monitor for continuous glucose concentrations; phospholipids or surfactants can form Vesicles in solution, in which lipophilic chain of the parent molecular form lipophilic region, Hydrophilic group form Hydrophilic region, Bilayer structure of Vesicles Can be used as Membrane model and the drug carrier.To develop the chemical sensor we introduced fluorescent chromophore and identifiable boric acid functional groups in the parent molecule to reach the above purpose.This paper designed and synthesised three new parent compounds: N-(boronobenzyl)-8-hexadecyloxyquinoliniumbromide(BHQB); N-(boronobenzyl)-8- cholesterolethoxyquinolinium bromide (BCQB);(p-((5-dodecyloxy-1-oxy) naphtha- lene) methyl phenylboronic acid DNMPBA)。To study the difference between Vesicles sensor and small molecule sensor we synthesized N-(boronobenzyl)-8-methoxyquinol- inium bromide (BMQB). Characterization by NMR of the reaction product of step-by-step to prove that its structure is correct, on the four end products has been characterized by elemental analysis to determine its composition. We Characterized each reaction product by NMR to prove that the structure is correct, characterized the four end products by elemental analysis to determine its composition. BHQB、BCQB and DNMPBA are typical amphiphile molecole, which can form the Aggregation structure after ultrasonic vibration in the selective dilute solution of methanol or tetrahydrofuran and water. We used emission scanning electron microscope to observe the three parent compounds’morphology of aggregates are spherical, the diameter is 70-500 nm ,30-100 nm and 40-150 nm Separately. We used differential thermal scanners to test the three substances from the gel state to liquid state, the temperature is 56.8℃, 52.4℃and 61.6℃. Proved that the three substances in the selective solution formed spherical vesicle structure.We studied two highly similar organic compounds BMQB and BHQB , in the mixed solution The proportion of Methanol and water was 1:1 BHQB formed spherical vesicles ,however, BMQB was decentralized system.We studied the relationship between the Fluorescence spectrum of BHQB vesicle and the pH of the system. As the pH increased from 3 to 11, the fluorescence intensity of BHQB vesicles decreased at 508nm, increased at 425nm. I425nm / I508nm increased from 0.06 to 0.27 .Under the concentration condition of 10-5M(Ф=0.5 ,pH=7.4),we tested BHQB Vesicles’detection effect on sugar.Similar to the Change of pH , the fluorescence intensity of BHQB vesicles decreased at 508nm, increased at 425nm.When the glucose concentration of the system was 150 mM , the Ix / I0 value under BHQB vesicles turned into 4.12-fold compared with the non-sugar situation, while under the same conditions fructose changed 2.35-fold . The changes scope of glucose was generally less than 10mM, at this time the Ix / I0 value of BHQB vesicles compared with the non-sugar changes thrned into 1.58-fold, under the same conditions fructose changed 1.38-fold.BHQB Vesicle system’selectivity for glucose is better that fructose, which was not common in the past report. added 150mM glucose to BMQB small molecule system, the Ix / I0 value was 2.91-fold, added 150mM fructose to it ,the Ix / I0 value was 1.65-fold. When the amount of sugar was less than 10 mM ,the changes hardly occurred.Cholesterol and its derivatives are important components of material organisms,which have many physiological functions. We used cholesterol and Glycol ethers as hydrophobic groups to Synthesis parents compounds BCQB. We Prepared the BCQB methanol / water solvent selection into vesicles to detect the sugar(10-5M,Ф=0.5 ,pH=7.4). with the concentration of sugar increased, the fluorescence intensity of the vesicles decreased at 508nm, increased at 425nm, but changed slightly, The sensitivity to the sugar is low.The reason was the hydrophobic groups that connected to quinoline chromophore constrained quinoline chromophore’electronic mobile, the quinoline chromophore’electron cloud changed little After the formation of borate. Therefore fluorescence did not change significantly. DNMPBA vesicle reflected a certain selectivity to the changes of different sugar .when the concentration changed from 0 M to 2×10-2 M, the change rate of fructose ,glucose and Maltose is2.08-fold、1.84-fold、1.27-fold separatelly.Such selectivity was fructose> glucose> maltose. This is because D-glucose and D-fructose is six-ring structure, but when they dissolve in water this type exist the transformation from pyranose to furanose .The boric acid structure compounds and furanose form a borate more easily. Maltose was a typical second sugar, pyranose can not change into furanose in solution, so after its interaction with the DNMPBA vesicle, the change was far less than fructose and glucose.With in-depth understanding of DNMPBA vesicle system, the same conditions: 1, the existence of carbohydrate; 2, rule out the dissolved oxygen with nitrogen,the singlet naphthalene in the system changed little. While at 408nm Department the excimer emission peaks have emerged.With the single-sugar increased, the excimer emission peak was also enhanced significantly. We use the intensity of excimer emission and the intensity of singlet changes ratio as the basis for detection of sugar, got a new detection method. Glucose or fructose concentrations change from 0 to 5×10-5 M, I 408nm / I344nmwere increased from 0 to 3.04 and 4.51. Then we changed The ratio of tetrahydrofuran and water in the DNMPBA vesicle solution ,found that I408nm/I344nm changed when changed the amount of sugar . It’sΦ=0.5﹥Φ=0.6﹥Φ=0.8. Such differences for two reasons:Φwas smaller the water was more, the hydrophobic co-operational function of DNMPBA Parents molecule was stronger, DNMPBA Naphthalene was closer; Sugar was not soluble in tetrahydrofuran, so more tetrahydrofuran, the interaction of sugar and DNMPBA vesicles was more difficulty. Therefore, increasing the water in the solution would improve the detection sensitivity in the situation that DNMPBA Molecular dissolved .We used the intensity of excimer emission and the intensity of singlet changes ratio as the basis for the detection of sugar. This kind of sensitivity of detection reached 10-5-10-6M.Through the above studies ,we see that the vesicles sensors which include group identification and are formed by parent-molecules can solve the continuity of the blood glucose test, prepare long-term implantable devices.It Makes the blood glucose testing on diabetic patients in time is possible.更多还原