【作者】 黄卉；

【导师】 苏星光；

【作者基本信息】 吉林大学 ， 分析化学， 2012， 博士

【摘要】 共轭聚合物（Conjugated Polymers，CPs）是指碳链骨架上含有单、双键交替共轭体系的聚合物。作为高性能的光学电学材料，CPs拥有广泛的应用前景，已被广泛地应用于发光二极管、电化学电池、塑料激光器、太阳能电池、场效应晶体管等。同时，基于CPs的荧光传感器也受到越来越多的关注。本论文第一章中，我们首先概括了共轭聚合物的发展历史、结构性质，介绍了其猝灭原理并研究了CPs标志性的荧光特征—超猝灭。接着，我们综述了基于CPs的荧光传感器在离子检测、生物分子检测、爆炸物质检测方面的应用。最后我们对基于CPs的荧光传感器的应用前景进行了展望，并设计了几种基于水溶性共轭聚合物PPESO₃的新型荧光传感器，此传感器不但可以用于苯醌和对苯二酚和过氧化氢的高灵敏检测，还能作为生物传感器检测儿茶酚胺，以及免标记turn-on检测生物硫醇.第二章中，我们利用了一种简便的路线成功地合成了PPESO₃，并对其进行了表征。还详细研究了PPESO₃的基本光学性质以及其荧光的影响，为PPESO₃荧光传感器的制备和应用做了良好的铺垫。并利用水溶性共轭荧光聚合物PPESO₃在乙醇：水=1：1的溶剂中实现了对稀土离子La（III）的高灵敏检测。第三章中，我们利用制备的PPESO₃建立了一种新型的荧光传感器，此传感器可以灵敏地检测了苯醌，对苯二酚和过氧化氢：由于共轭荧光聚合物PPESO₃可以被苯醌猝灭，并且PPESO₃的荧光强度在猝灭前后之比（I₀/I）与苯醌的浓度成正比，在1.0×10^-63.0×10^-3mol/L浓度区间内满足斯特恩方程，从而可以实现对苯醌的检测。利用H₂Q在HRP和H₂O₂共同存在条件下能够被催化氧化为醌的形式，使PPESO₃超猝灭，可以实现对H₂Q的检测。另一方面，在HRP和H₂Q同时存在时，加入具有氧化性的过氧化氢，也能够产生苯醌超猝灭PPESO₃，可以实现对于H₂O₂的检测。我们的荧光传感器检测对苯二酚和过氧化氢的线性范围分别是1.0×10^-62.0×10^-3和6.0×10^-62.0×10^-3，检出限分别为5.0×10^-7和1.0×10^-6。灵敏度高于以往文献中的报导。另外，利用BQ对于PPESO₃的猝灭和在催化剂存在时H₂Q对于PPESO₃的猝灭，能够检测苯酚的氧化程度。该体系为水溶性荧光共轭聚合物传感器的发展提供了基础，可以广泛用于分析检测含有或化学过程中产生苯醌的物质。PPESO₃不但可以对废水中的醌类和酚类进行检测，还可以作为生物传感器检测生物体内物质。第四章中，我们建立了以共轭聚合物基础，结合过氧化物酶和过氧化氢构成的生物传感器，利用儿茶酚胺的氧化产物对于PPESO₃的荧光猝灭作用实现了对儿茶酚胺的灵敏性检测。多巴胺、肾上腺素和去甲肾上腺素的线性范围分别为5.0×10^-71.4×10^-4，5.0×10^-65.0×10^-4和5.0×10^-65.0×10^-4mol/L。检出限分别是1.4×10^-7mol/L，1.0×10^-6和1.0×10^-6mol/L。在实际样品检测实验中，我们利用该体系检测了人血清中的DA，AD，NE，实验数据的精确度于HPLC-MS方法对比，结果令人满意。表明此方法能够在血清中检测DA，为将来用于药物制剂的达标检测，药物在体内或在细胞中的运输和缓释等提供了可行性。二价铜离子能够猝灭PPESO₃，而且猝灭后形成一个稳定的离子复合物。这是由于PPESO₃和铜离子之间的电子转移导致的。当加入生物硫醇（GSH或Cys）时，由于硫醇与铜离子之间形成Cu-S键，这种化学键的结合能力远大于离子间的静电力，因此Cu₂₊远离PPESO₃从而荧光恢复。基于此，我们成功的构建了一个免标记的turn-on生物硫醇传感器。此检测过程简单，无需标记，而且Cu-S键的结合力强，很容易形成，灵敏度很高，荧光恢复接近90%。对半胱氨酸和谷胱甘肽的检出限分别为4.0×10^-8和4.5×10^-8mol/L，足以检测人体血清中的生物硫醇。另外，该体系对于其它氨基酸等干扰物质相比选择性良好，并且可以用于实际样品人血清中硫醇检测。此体系还可以用于活肝癌细胞的生物成像，观察到了细胞中硫醇浓度分布。因此本项研究为CPs用于生物体系检测小分子以及细胞成像技术开辟了新的研究领域。更多还原

【Abstract】 A conjugated system is a system of connected p-orbitals with delocalizedelectrons in compounds with alternating single and multiple bonds, which in generalmay lower the overall energy of the molecule and increase stability, which attractsmore and more interest. The first chapter of this thesis outlines the history anddevelopment of conjugated polymer, the structure and classify. The fluorescencequench mechanism and the research method were discussed. For CPs application，the reported fluorescent sensors based on CPs were listed （ion detection,biomolecular detection, explosive substance detection and bio-imaging applications）.And the research significance of this work is discussed.We used a facile sysnthetic route for preparing fluorescent conjugated polymerPPESO₃in chapter two, which avoided the dealkylation step with BBr3. We alsoinvestigated the fluorescence spectroscopy and absorption spectroscopy of PPESO₃.Both fluorescence enchance and quenching of PPESO₃were studied detailedly which is a preparation for later study in the thesis.In chapter three, a sensitive and simple detecting system was developed forquantitative analysis of both hydroquinone （H₂Q） and hydrogen peroxide （H₂O₂）,based on the successful combination of horse radish peroxidase （HRP） andwater-soluble conjugate fluorescence polymers PPESO₃. In the presence of HRP andH₂O₂, H₂Q could be oxidized to1,4-benzoquinone （BQ）, an intermediate, which playsthe main role in the enhanced quenching of the photoluminescence （PL） intensity ofPPESO₃. The quenching PL intensity of PPESO₃（I0/I） was proportional to theconcentration of H₂Q and H₂O₂in the range of1.0×10^-6to2.0×10-3mol/L （R2=0.996）and6.0×10^-6to2.0×10-3mol/L （R2=0.999）, respectively. The detection limit for H₂Qand H₂O₂was5.0×10^-7mol/L and1.0×10^-6. The present fluorescence quenchingmethod was successfully applied for the determination of H₂Q in the lake water,rainwater, tap-water and chemical plant waste water samples. Compared withprevious reports, the fluorescence quenching approach described in this work issimple and rapid with high sensitivity, which has a potential application for detectingvarious analytes which can be translated into quinone.The above study indicates that the enzymatic reaction product ofhydroquinone–quinone can efficiently quench the photo-luminescence intensity ofPPESO₃. Considering that dopamine is a catecholamine that contains adihydroxybenzene group, we developed a sensitive water-soluble fluorescentconjugated polymer biosensor for catecholamine （dopamine DA, adrenaline AD andnorepinephrine NE） in chapter four. In the presence of horse radish peroxidase （HRP） and H₂O₂, catecholamine could be oxidized and the oxidation product ofcatecholamine could quench the photoluminescence （PL） intensity of PPESO₃. Thequenching PL intensity of PPESO₃（I0/I） was proportional to the concentration of DA,AD and NE in the concentration ranges of5.0×10^-7to1.4×10^-4,5.0×10^-6to5.0×10^-4,and5.0×10^-6to5.0×10^-4mol/L, respectively. The detection limit for DA, AD and NEwas1.4×10^-7mol/L,1.0×10^-6and1.0×10^-6mol/L, respectively. The PPESO₃-enzymehybrid system based on the fluorescencequenching method was successfully appliedfor the determination of catecholamine in human serumsamples with good accuracyand satisfactory recovery. The results were in good agreement with thoseprovided bythe HPLC-MS method.In chapter five, we developed a new one-step turn-on sensor for the sensitive andselective detection of glutathione （GSH） and cysteine （Cys）. The photoluminescenceintensity of PPESO₃could be quenched by Cu（II） due to the strong electrostaticinteraction and electron transfer between PPESO₃and Cu2+. In the presence ofbiothiols, such as GSH and Cys, Cu（II） preferred to react with biothiols to form theCu（II）-S bond due to the strong affinity between Cu（II） and thiols. The recovered PLintensity of PPESO₃（Ir/I0） was proportional to the concentration of GSH or Cys in theconcentration ranges of1.0×10^-7～1.5×10-5mol/L and2.0×10^-7～2.0×10-5mol/L,respectively. The detection limit for GSH and Cys were4.0×10^-8and4.5×10^-8mol/L, respectively. In addition, the established method showed a high selectivity forbiothiols among other twelve amino acids without biothiols. Furthermore, thePPESO₃-Cu（II） system as a fluorescence probe was successfully used for fluorescence imaging of biothiols in the HepG2cells, which presents a potential application inbioimaging field.更多还原