用于检测铁(Ⅲ)离子的新型共轭聚合物荧光探针

A Novel Conjugated Polymer Fluorescent Probe for Detection of Iron( Ⅲ)

以1,10-邻菲咯啉为原料合成了1,10-菲咯啉-5,6-二酮,并进一步与对苯二胺通过席夫碱反应合成共轭聚合物荧光探针。通过核磁共振、红外光谱、黏度等对聚合物进行表征,通过紫外吸收与荧光发射光谱研究了此聚合物对金属离子的识别性和敏感性。对1,10-邻菲咯啉与聚合物探针配位Fe3＋前后的吸收光谱、荧光光谱以及红外光谱进行对比研究。实验结果表明：在聚合物溶液中,加入Fe3＋后溶液由无色变为浅红棕色,可实现肉眼识别检测Fe3＋,而紫外吸收和发射光谱的变化表明此聚合物荧光探针对Fe3＋具有较好的选择性和灵敏性;其对加入的Fe3＋能瞬间响应（〈1 s）,完全响应时间为30 min,对Fe3＋的线性检测范围为0~12.5μmol/L,检出限为2.72μmol/L。Fe3＋对探针的猝灭常数为1.52×104L/mol。通过分析聚合物荧光探针与Fe3＋的作用机理,绘制出聚合物荧光探针与Fe3＋作用后的结构示意图。

A conjugated polymer fluorescent probe was synthesized by Schiff reaction using the compounds of p-phenylenediamine and 1,10-phenanthroline-5,6-dione prepared with 1,10-phenanthroline. This polymer was characterized by means of1 H NMR,IR,viscosity,etc. The selective and sensitive properties of the polymer to detect metal ions were investigated by UV- vision absorption and fluorescent spectroscopy. Furthermore,in order to explore the interaction mechanism between the polymer fluorescent probe and Fe3 ＋,the UV- Vis absorption and fluorescent spectra and IR absorption spectra of 1,10-phenanthroline-5,6-dione and polymer fluorescent probe at the presence and absence of Fe3 ＋were measured and analysed. The experiment results showed that the colours of the solution changed from colourlessness to reddish brown only at presence of Fe3 ＋,which indicating that Fe3 ＋could be detected by naked eyes. Moreover,the change of the UV- vision absorption and fluorescent spectra of the polymer revealed that the polymer fluorescent probe owned a high sensitivity and selectivity for the detection of iron（ Ⅲ）. The instant response time was less than 1 s,and the abslute response time was 30 min. Moreover,the linear response range of iron（ Ⅲ） was in the range of 0-12. 5 μmol / L and the detection limit was 2. 72 μmol / L. The quenching constant of Fe3 ＋to the probe was 1. 52 × 104 L / mol. In addition,the possible interactional diagrammatic sketch between the polymer fluorescent probe and iron（ Ⅲ） was drawn by analysing the interactional mechanism of the polymer probe- Fe3 ＋complex.