在双波长下识别Fe3+的一种新型可视化荧光探针的合成及性能

Synthesis and Properties of A Novel Colorimetric Fluorescent Probe for Fe3+ at Dual Emission Wavelengths

合成了一种新型四苯乙烯-罗丹明化合物L,通过紫外-可见吸收光谱、分子荧光光谱、裸眼和循环伏安分析法等分别研究了化合物L的聚集诱导发光性能、对金属阳离子的识别性能和电化学性能。实验结果显示:化合物L在乙醇-水的混合溶剂中表现出典型的聚集诱导发光性能;L在EtOH/H2O(V∶V,1∶1,Tris-HCl,pH=7.0)溶液中随Fe^3+的加入,化合物L的EtOH/H2O(V∶V,1∶1,Tris-HCl,pH=7.0)溶液显示出明显的颜色变化,由无色变成红色,除Al^3+、Cr^3+略微变红外,其他金属离子无明显变化,这表明化合物L可作为裸眼识别Fe3+的探针;当选用激发波长350nm时,在508nm处的荧光发射强度发生猝灭,猝灭比为87.5%,检出限为4.56×10^-6mol/L;激发波长为530nm时,在582nm处荧光发射强度呈增大趋势,较加入前增大了49.6倍,检出限可达7.4×10^-7mol/L。由此可见,L在用不同激发波长激发时,在两个不同荧光发射波长下分别实现了对Fe^3+的“turn-off”和“turn-on”识别,因此L可作为一种具有高灵敏性和专一选择性的可视化Fe^3+荧光探针。并经Jobs曲线、紫外和荧光滴定、核磁滴定、扫描电镜初步确定了探针L和Fe^3+的络合机理,探针L和Fe^3+的络合比为2∶1,整个测试在中性条件下进行,使得该类探针在生物体系或环境中有潜在的应用价值。且它的电离势为5.77eV,电离势与正电极的功函数(5.5eV)较匹配,有望开发成为空穴传输材料。电子亲合势为3.71eV,比常见的电子传输材料PBD(EA=2.82eV)的电子亲和能大,有望开发为电子传输材料,所合成的化合物也可作为一类具有潜在应用价值的光电材料。

A novel derivative L based on tetraphenylethylene-rhodamine was synthesized. FT-IR, NMR, UV-Vis and solution fluorescence and cyclic voltammetry electrochemical analysis were used to study the structure,optical properties, recognition ability of compound L to metal ions and electrochemical properties. The experimental results showed that compound L possessed a significant aggregation-induced emission(AIE) characteristic in different V (EtOH)∶ V (H2O) mixed solvents. When 10 equiv. of Fe^3+ was added to the solution containing probe, the solution of compound L in EtOH/H2O( V ∶V , 1 ∶1, Tris-HCl, pH=7.0) changed the color from colorless to red. Except that the addition of Al^3+ or Cr^3+ slightly changed the solution color to reddish, the addition of other metal ions did not induce significant color changes. The fluorescence spectra showed that when fluorescence emission wavelength at 508 nm was quenched with a quenching ratio of 87.5% and the detection limit of Fe 3+ was as low as 4.56×10^-6 mol/L. Interestingly, the fluorescence intensity at 582 nm increased with the addition of Fe^3+, which was increased by 49.6 times with the detection limit of Fe^3+ was as low as 7.4×10^-7 mol/L, which achieved the “turn-off” and “turn-on” visual detection of Fe^3+ at the maximum fluorescence emission wavelengths of 508 nm and 582 nm, respectively. Thus, the probe L is a highly sensitive, specific, and visible fluorescent probe for the detection of Fe^3+. The mechanisms have been supported by reversibility of the Job s plot, UV-vis and fluorescence titrations, 1H NMR spectroscopic studies and SEM images. The complexing ratio of probe L with Fe^3+ was determined to be 2 ∶1. The test was conducted in neutral aqueous solutions, which indicated that the probe L could be applicable to the research on the biological and environmental applications associated with Fe^3+. Cyclic voltammetry electrochemical analysis was used to study their electrochemical properties, the results showed that L had good hole transporting ability and good electron transporting capability. L can be used as a optoelectronic material.