Design of Supramolecular Cyclodextrin Complex Sensors and Construction of Functional Interfaces

本研究设计了具有不同烷基长度的苯并-15-冠-5(B15C5)偶氮探针，其烷基长度分别为n=1(C1-Az)、n=2(C2-Az)和n=4(C4-Az)，用于构建基于超分子偶氮探针/γ-CyD络合物的新型水中光信号转导体系。对于所有的CN-Az探针，UV-Vis光谱都表现出K~(++)选择性的蓝移，在较长的波长上摩尔吸光系数降低，表明CN-Az与K~(2+)选择性形成2：1的络合物。而在ICD光谱中，观察到不同的光谱响应。因此，对于C1-Az和C2-Az，随着烷基链长从甲基增加到乙基，对K~(++)选择性ICD的反应明显增强。然而，对于具有较长丁基链的C4-Az，发现TMA^+而不是K^+具有异常强烈的ICD反应。UV-Vis和ICD之间不同的光谱响应归因于形成了不同模式的CyD包合物。此外，在没有γ-CyD存在的情况下，C4-Az对K~+具有独特的响应函数。讨论了这些结果与它们的超分子络合物结构的关系。为了手性识别水中的糖，开发了联苯基硼酸荧光团(BPB)/CyD复合传感器。BPB在高pH区(pH 9.3以上)表现出对糖结合的荧光发射响应。利用该pH范围，考察了CyD对BPB对果糖的D/L识别能力的影响。结果表明，在没有环糊精的情况下，或在包结腔较小的β-环糊精存在的情况下，没有D/L选择性。而当γ-CyD包结空腔较大时，γ-CyD络合物对D(-)-异构体的选择性提高了一倍。这是一种新的基于CyD中羟基多点相互作用的超分子CyD络合物传感器的识别函数。

In this study, benzo-15-crown-5 (B15C5) azoprobes possessing different alkyl chain lengths of n=1 (C1-Az), n=2 (C2-Az), and n=4 (C4-Az) have been designed for construction of novel photosignal transduction systems in water based on supramolecular azoprobe/γ-CyD complexes. For all Cn-Az probes, the UV-Vis spectra exhibited a K^+-selective blue shift with reduction of molar absorptivity in the longer wavelength, indicating a selective 2:1 complex formation of Cn-Az with K^+. While in the ICD spectra, different spectral responses were observed. Thus for C1-Az and C2-Az, the K^+-selective ICD response was clearly intensified by increasing the alkyl chain length from methyl to ethyl. However for C4-Az possessing longer butyl chains, an abnormally strong ICD response was noted for TMA^+ instead of K^+. These different spectral responses between UV-Vis and ICD were ascribed to the formation of different mode of CyD inclusion complex. In addition, C4-Az was found to have a unique response function for K^+ in the absence of γ-CyD. These results were discussed in relation to their supramolecular complex structures. For chiral recognition of sugars in water, biphenylboronic acid fluorophore (BPB)/CyD complex sensors have been developed. BPB showed fluorescence emission response upon sugar binding at high pH regions (above pH 9.3). By using this pH regions, effect of CyD upon the D/L recognition ability of BPB for fructose have been examined. The results indicated that no D/L selectivity was noted in the absence of CyD or the presence of β-CyD possessing smaller inclusion cavity. Whereas in the presence of γ-CyD having larger inclusion cavity, twice higher selectivity for D(-)-isomer was found to appear for BPB/γ-CyD complex. This is a novel recognition function of supramolecular CyD complex sensors based on multi point interaction of OH groups in CyD.