摘要
将发光性质优异的香豆素基团作为荧光信号单元引入有机配体H_(3)L,与过渡金属离子Zn(Ⅱ)配位自组装,构建了一例金属-有机笼状化合物Zn-L,利用主客体氢键弱作用实现了对氨基葡萄糖的选择性识别。高分辨质谱和紫外-可见吸收光谱结果显示,金属-有机笼状化合物Zn-L结构可能为M_(6)L_(4)的八面体构型,12个香豆素基团均匀分布在笼状结构的顶点,空腔带有窗口,允许尺寸合适的客体分子自由进出。主客体核磁滴定显示,氨基葡萄糖通过多重氢键作用与笼状结构相结合;高分辨质谱测试表明,笼状结构与氨基葡萄糖形成了物质的量比为1∶2的主客体包合物。荧光滴定光谱拟合结果显示,络合常数为1.6×10^(8) L^(2)/mol^(2),证实主客体间具有较强的络合作用,有利于笼状结构对氨基葡萄糖的选择性识别。氨基葡萄糖分子对Zn-L荧光强度淬灭高达93%,最低检测限为0.23μmol/L,而其他9种常见生物糖类小分子只能淬灭5%~20%,Zn-L对氨基葡萄糖分子具有选择性荧光响应,且可以应用于活细胞中氨基葡萄糖的荧光成像。
A metal-organic cage compound Zn-L was constructed by introducing coumarin group with excellent luminescent properties as fluorescence signal unit into organic ligand H_(3)L and self-assembling with transition metal ion Zn(Ⅱ). Compound Zn-L realized selective recognition of glucosamine via weak host-guest hydrogen bonding interaction. The results of high-resolution mass spectroscopy and UV-Vis absorption spectroscopy showed that the metal-organic cage compound had a M_(6)L_(4) octahedral structure,with twelve coumarin groups uniformly distributed at the vertical positions of the cage, and a large cavity with opening windows that allowed free ingress and egress of the guest molecules with suitable size. 1HNMR titration indicated that glucosamine was combined with cage structure through multiple hydrogen bonding. High resolution mass spectrometry test suggested that a molar ratio of 1∶2 host-guest inclusion complex was formed between metal-organic cage Zn-L and glucosamine. The results of fluorescence titration spectra fitting showed that the complexation constant was 1.6×10^(8) L^(2)/mol^(2),confirming the strong complexation between host and guest, which was conducive to the selective recognition of glucosamine by the cage structure. Glucosamine molecules quenched up to 93% of the fluorescence intensity of Zn-L, and the detection limit was 0.23 μmol/L, while the other nine common biological carbohydrate molecules could only quench 5%~20% of the fluorescence intensity, indicating that Zn-L had a highly selective fluorescence response to glucosamine molecules and could be used for fluorescence imaging of glucosamine in living cells.
作者
李亚楠
赵亮
蔡俊凯
段春迎
LI Ya'nan;ZHAO Liang;CAI Junkai;DUAN Chunying(State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024,Liaoning,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2021年第10期2004-2011,共8页
Fine Chemicals
基金
国家自然科学基金(21890381,21820102001)。
关键词
金属-有机笼
主客体作用
氨基葡萄糖
荧光响应
选择性识别
功能材料
metal-organic cage
host-guest interaction
glucosamine
fluorescence response
selective recognition
functional materials
