一种锌金属有机骨架(Zn-MOF)材料的荧光光谱法在食品Fe~(3+)检测中的应用

以2,5-呋喃二甲酸和六水硝酸锌为原料,N,N-二甲基甲酰胺为溶剂合成一种锌金属有机骨架材料[(Me_2NH_2)_2Zn_3(fdc)_4]_n·DMA(Zn-MOF)。用荧光光谱法对该材料的荧光特性进行研究,发现该材料在波长379 nm和398 nm处有很强的荧光发射峰。考察食品中可能存在的16种不同金属离子对该材料荧光强度的影响,研究表明,Fe~(3+)能选择性地令该材料产生荧光淬灭现象。此外,考察Fe~(3+)浓度、浸泡时间和2种混合金属离子(Fe~(3+)-M~(+/2+/3+))对荧光淬灭敏感度的影响。结果表明,锌金属有机骨架材料对Fe~(3+)具有高度选择性传感功能,可作为荧光探针应用到食品Fe~(3+)的检测中,并可以高效地检测出Fe~(3+)。

Determination of Fe3+ in Foods by Fluorescence Spectroscopy Using a Zinc-Based Metal-Organic Framework Material

In this paper, a zinc-based metal organic framework, [(Me2NH2)2Zn3(fdc)4]n·DMA (Zn-MOF), was prepared from 2,5-furandicarboxylic acid and Zn(NO3)2·6H2O in N,N-dimethylformamide (DMF) under solvothermal condition. Fluorescence spectroscopic analysis revealed that the material showed emission maxima at 379 and 398 nm. The effects of 16 metal ions often coexisting in foods on the fluorescence intensity of the material were explored. The results indicated that Fe3+ could selectively quench the fluorescence of the material. In addition, the effects of Fe3+ concentration, soaking time and metal ion mixtures (Fe3+-M+/2+/3+) on the sensitivity of fluorescence quenching were also investigated. Our results showed that Zn-MOF exhibited high selectivity for Fe3+. Thus, this Zinc-based metal-organic framework material could be used as a fluorescent probe for the determination of Fe3+ in foods.