一种罗丹明6G类“Off-On”型Fe^(3+)比色荧光探针

An “Off-On” Fe^(3+) Ions Colorimetric and Fluorescent Probe Based on Rhodamine 6G Derivative

设计合成了一种基于罗丹明6G的新型比色荧光探针(RG),并通过核磁共振氢谱、碳谱和质谱进行了表征。该探针在pH=6的Tris-HCl缓冲溶液中可与Fe^(3+)作用,溶液由无色变为粉红色,在530nm处产生强吸收,同时在557nm处发射强荧光。通过金属离子选择性实验,发现探针RG对Fe^(3+)有高选择性;此外,探针溶液530nm的吸光度和557nm的荧光强度与Fe^(3+)浓度呈良好的线性关系,检出限分别为1.26和3.87μmol/L。Job’s曲线分析表明探针分子与Fe^(3+)的反应摩尔比为1∶1。此外,以乙二胺四乙酸为络合剂实现了探针分子的重复使用。该探针可用于实际水样中Fe^(3+)的精准检测。

The colorimetric and fluorescent probe(RG) based on Rhodamine 6 G was designed and synthesized, and its structure was characterized by ~1H NMR,13C NMR and MS. The probe can react with Fe^(3+)ions in Tris-HCl buffer solution of pH=6. The solution changed from colorless to pink, and had a strong absorption at 530 nm and emitted strong fluorescence at 557 nm. Selectivity experiments of metal ions showed that the probe molecule can highly selectively recognize Fe^(3+)ions. There were good linear relationships between the absorbance at 530 nm and fluorescence intensity at 557 nm of the probe(RG) solution and the Fe^(3+)ions concentrations. The limits of detection were found to be 1.26 μmol/L and 3.87 μmol/L, respectively. The Job’s curve demonstrated that the reaction molar ratio of probe molecules to Fe^(3+)was 1∶ 1. In addition, the reusability of the probe was achieved by using ethylenediaminetetraacetic acid as a chelating agent. The probe can be used to accurately detect Fe^(3+)ions in real water samples.