采用溶剂热合成方法, 合成了一例金属-有机框架{［Zn2(OH)(TZI)·2H2O］·6DMF}n (1)(TZI为5-四氮唑间苯二甲酸), 并利用单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射等手段对化合物进行了结构表征。单晶X射线衍射结果显示配合物1呈现出三维孔道结构, 并且孔道中存在未配位的羧基和配位的水分子。随后通过后合成法将Eu(Ⅲ)离子引入到框架中得到具有红光发射特征的Eu(Ⅲ)@1。在275 nm的激发光下, Eu(Ⅲ)@1存在两组荧光发射, 第一组在418 nm处的宽峰为配合物1的荧光发射, 荧光源于有机配体的吸收和发射; 第二组五个发射峰为Eu(Ⅲ)离子的红色特征发射峰, 其主峰为619 nm。尿液中其他成分抗干扰性实验结果表明, Eu(Ⅲ)@1荧光探针对于生物标记物1-萘酚非常敏感, 能够导致红色荧光猝灭(619 nm), 并伴有青色荧光增强(465 nm), 对1-萘酚具有高选择性。荧光滴定实验结果显示Eu(Ⅲ)@1基于465和619 nm处荧光发射峰对1-萘酚的检测限分别为6.95 μmol/L和1.75 mmol/L。

A metal-organic framework complex {［Zn2(OH)(TZI)·2H2O］·6DMF}n (1) (TZI=5-tetrazolylisophthalic acid) was successfully isolated under solvothermal conditions. The structure of the complex was characterized by single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction. Single crystal X-ray diffraction study reveals that 1 displays a 3D structure with channels, where exist uncoordinated carboxylate groups and coordinated water molecules. Subsequently, through post-synthesis method, a Eu(Ⅲ)@1 with red fluorescence emission was obtained by introducing Eu(Ⅲ) into framework of 1. Under 275 nm wavelength excitation, Eu(Ⅲ)@1 possesses two groups of fluorescence emission. In the first group, the wide peak at 418 nm is the fluorescence emission of 1, which origins from the absorption and emission of the organic ligand. While, the second group of five emission peaks is the red characteristic emission peak of Eu(Ⅲ) ion, with main peak of 619 nm. The results of anti-interference experiments of other components in urine show that Eu(Ⅲ)@1 fluorescent probe is very sensitive to the biomarker 1-naphthol, and can lead to red fluorescence quenching (619 nm), accompanies by cyan fluorescence enhancement (465 nm), and has high selectivity for 1-naphthol. Fluorescence titration results show that the detection limits of Eu(Ⅲ)@1 for 1-naphthol based on fluorescence emission peaks at 465 and 619 nm are 6.95 μmol/L and 1.75 mmol/L, respectively.