【作者】 谭津；

【导师】 严秀平；

【作者基本信息】 南开大学 ， 分析化学， 2009， 博士

【摘要】 本论文利用分子印迹材料对结构类似物质具有交叉响应性的特点,将分子印迹技术应用于荧光传感器阵列,以介孔硅材料为固体基质,发展了基于介孔硅材料的荧光分子印迹传感器阵列的新方法,分别用于金属离子与糖类分子的识别。本论文研究工作的主要内容与创新点表现在以下几个方面:（1）合成了一种简单的具有4,7位取代2,1,3-苯并二唑结构的新化合物。基于扭曲的分子内电荷转移（twisted intramolecular charge transfer,TICT）,该化合物可以在CH₃CN-H₂O混合溶剂中有效地选择性识别Hg²⁺和Cu²⁺。UV-vis吸收光谱和溶液颜色的变化为我们提供了一种简单而快速地检测这两种离子的方法。其它一些碱金属、碱土金属、过渡元素及重金属离子包括Na⁺、Mg²⁺、Mn²⁺、Co²⁺、Ni²⁺、Ag⁺、Zn²⁺、Pb²⁺与Cd²⁺对Hg²⁺或Cu²⁺测定的干扰较小。本工作不仅是对Hg²⁺和Cu²⁺比色检测技术的补充,也拓展了4,7位取代2,1,3-苯并二唑类化合物的应用范围。本工作的初衷是将4-巯基-2,1,3-苯并二唑结构功能化到三乙氧基硅烷,从而利用得到的含有巯基的荧光功能单体发展汞形态分析用的荧光印迹传感器阵列。实验中发现合成的新化合物4-巯基-2,1,3-苯并二唑不会与3-氨基丙基三乙氧基硅烷发生反应而是在该碱性硅氧烷的存在下与自身发生反应。虽然本工作的初衷无法实现,但是我们发现得到的含巯基的2,1,3-苯并二唑衍生物对Hg²⁺和Cu²⁺有比较好的比色响应,可以作为一种快速选择性识别Hg²⁺和Cu²⁺的比色化学传感器。（2）报道了一种基于介孔硅基质的荧光增强型的离子印迹传感器阵列,可以用于几种金属离子的识别。采用8-羟基喹啉功能化的三乙氧基硅烷与四乙氧基硅烷共聚的方法分别合成了Zn²⁺印迹、Cd²⁺印迹以及非印迹的介孔硅材料。通过荧光光谱滴定实验与一种Langmuir型非线性拟合计算得到了三种材料与两种模板离子的结合常数。得到的三种材料对Zn²⁺与Cd²⁺这两种印迹模板离子以及Mg²⁺、Ca²⁺、Al³⁺这三种非模板离子有着不同程度的荧光增强响应。由这三种材料组成的荧光增强型传感器阵列可以识别这五种金属离子。利用具有交叉响应性的印迹效果,只使用一种普通的荧光染料（8-羟基喹啉）就可以达到识别几种金属离子的目的。本工作不仅证明了印迹传感器阵列的选择性源于印迹过程本身,而且将印迹传感器阵列的应用领域延伸到了本身不会产生荧光信号的分析物。（3）构建了一种基于介孔硅基质的荧光染料置换型糖印迹传感器阵列,可以用于几种糖类分子的识别。采用苯硼酸功能化的三乙氧基硅烷与四乙氧基硅烷共聚的方法分别合成了D-果糖印迹、D-木糖印迹以及非印迹的介孔硅材料。通过荧光光谱滴定实验得到了三种材料与八种普通单糖（D-果糖、D-木糖、D-阿拉伯糖、D-葡萄糖、D-半乳糖、D-甘露糖、L-山梨糖与D-核糖）的Stern-Volmer猝灭常数,研究了三种材料与这八种糖的不同作用情况,证明了不同印迹材料对几种糖不同的响应模式为实现这些糖的识别提供了可能。由这三种材料组成的荧光传感器阵列可以识别十种糖（D-果糖、D-木糖、D-阿拉伯糖、D-葡萄糖、D-半乳糖、D-甘露糖、L-山梨糖、D-核糖、L-鼠李糖与麦芽糖）。结合指示剂置换技术与分子印迹技术,只使用一种普通的糖的受体（苯硼酸）和一种常用的荧光染料（茜素红）就可以达到识别十种糖的目的。此外,利用这种荧光印迹传感器阵列还实现了三种含糖的橙汁饮料的鉴别。更多还原

【Abstract】 In this dissertation an alternative route to conventional sensor arrays based on molecularly imprinted mesoporous silica is presented.We take advantage of imprinting effect to develop fluorescent imprinting sensor an’ays.A fluorescence turn-on sensor array for metal ions and a fluorescent indicator-displacement sensor array for saccharides are prepared respectively.The design,preparation and application of such fluorescent imprinting sensor arrays have been studied in detail, and are summarized as follows:（1） A simple twisted intramolecular charge transfer（TICT） chromogenic probe for rapid and selective detection of Hg²⁺ and Cu²⁺ was developed.The probe was composed of an electron-acceptor 4-fluoro moiety and an electron-donor 7-mercapto-2,1,3-benzoxadiazole species where the S together with the 1-N provided the soft binding unit.Upon Hg²⁺ and Cu²⁺ complexation,remarkable but different absorbance spectra shifts were obtained in CH₃CN-H₂O mixed buffer solution at pH 7.6,which can be easily used for naked-eye detection.The probe formed a stable 2:1 complex with Cu²⁺,and both 2:1 and 3:1 complexes with Hg²⁺.While alkali-,alkaline earth- and other heavy and transition metal（HTM） ions such as Na⁺,Mg²⁺,Mn²⁺, Co²⁺,Ni²⁺,Ag⁺,Zn²⁺,Pb²⁺ and Cd²⁺ did not cause any significant spectral changes of the probe.This finding is not only a supplement to the detecting methods for Hg²⁺ and Cu²⁺,but also adds new merits to the chemistry of 4,7-substituted 2,1,3-benzoxadiazoles.The initial purpose of this work was to develop a fluorescent molecular imprinting sensor array for mercury speciation.However,the synthesized 4-fluo-7-mercapto-2,1,3-benzoxadiazole reacted with itself under basic condition and formed a mercapto-2,1,3-benzoxadiazole derivative.It showed selective colorimetfic response toward Hg²⁺ and Cu²⁺ which made it a selective chromogenic probe for Hg²⁺ and Cu²⁺.（2） An ion imprinted mesoporous silica based fluorescence turn-on sensor array for discrimination of metal ions was developed.A novel fluorescent functional monomer containing an 8-hydroxyquinoline（8-HQ） moiety in combination with one-pot co-condensation method was employed to prepare fluorescent ion imprinted mesoporous silica.The imprinted materials for Zn²⁺ and Cd²⁺ as well as a control blank non-imprinted material（NIM） were synthesized.With the covalently anchored organic fluorophore in the inorganic mesoporous silica matrix,the binding of metal ions to the imprinting site was directly transformed into fluorescence signals.Both the imprinted materials displayed faster binding kinetics toward metal ions than NIM. Apparent binding constants（adsorption constants） for the materials with the metal ions in water were determined by a Langmuir-type analysis of the spectrofluorimetric titration data.The sensor array composed of the three materials allows discriminating the two template metal ions(Zn²⁺ and Cd²⁺) plus three non-template metal ions(Mg²⁺, Ca²⁺ and Al³⁺) at two different concentrations.This work proves that using a simple fluorescent receptor can provide a pattern based fluorescent sensing system by taking advantage of the imprinting effect.（3） A fluorescent indicator-displacement molecular imprinting sensor array based on phenylboronic acid functionalized mesoporous silica was developed for discriminating saccharides.D-Fructose imprinted material（FrulM）,D-xylose imprinted material（XylIM） together with a control blank nonimprinted material （NIM） were synthesized as the elements of the imprinting sensor array. Spectrofluorimetric titrations of the three materials with eight selected saccharides were carded out and Stem-Volmer quenching constants（Ksv） of NIM,FruIM and XylIM with the eight selected saccharides were obtained to investigate the interaction of the materials with saccharides.The present approach couples molecular imprinting technique to indicator-displacement strategy with the use of one conventional saccharide receptor（phenylboronic acid） and one commercially available fluorescent dye（Alizarin Red S.,ARS） as the indicator,and allows identifying two template saccharides（D-fructose and D-xylose） plus eight non-template saccharides （D-arabinose,o-glucose,D-galactose,D-mannose,L-sorbose,D-ribose,L-rhamnose and sucrose）.The principal component analysis（PCA） plot shows a clear discrimination of the ten tested saccharides at 100 mM and the first principal component possesses 94.8%of the variation.Besides,the developed saccharide imprinted sensor array is successfully applied to discriminating three brands of orange juice beverage.更多还原