两种双发光镧系金属有机框架材料联用检测水中农药残留

传统单发射响应发光传感器因发射光波长单一易受环境因素干扰而灵敏度低,以及双/多元镧系共掺杂发光传感器由于体系内镧系元素之间的能量转移效率易受温度等因素影响而使得检测灵敏度与选择性低,本文提出联用两种双发光镧系金属有机框架材料(lanthanide metal-organic frameworks,Ln-MOFs)实现水...

Detection of pesticide residues in water using two dual-emitting lanthanide metal-organic frameworks

To optimize the limitations of the exisiting fluorescent sensors: conventional single-emitting fluorescent sensors have limited sensitivity because the single emission can be easily affected by environmental factors, and the limited sensitivity and selectivity of dual/multiple-emitting fluorescent sensors because the internal energy transfer between lanthanide ions is susceptible to environmental factors like temperature. Two dual-emitting lanthanide metal-organic frameworks (Ln-MOFs) were utilized to achieve qualitative and quantitative detection of different pesticides simultaneously in water. Tb-MOF and Eu-MOF2 were synthesized, and their structures and properties were characterized. The prepared Ln-MOFs were used for qualitative and quantitative analysis of six pesticides (napropamide, picloram, imazethapyr, tebuconazole, flutriafol and benalaxyl). Combined with the UV-visible absorption spectra of each pesticide, the results showed that the energy transfer efficiency between Ln3+ and organic ligand in Ln-MOFs was regulated through interaction and competitive excitation energy absorption, and different pesticides had different effects on the energy transfer efficiency of organic ligand to Tb3+ and organic ligand to Eu3+. The values of lg(I₅₄₅/I₆₁₆) and lg(I₅₄₅/I₃₄₀) had a good linear relationship with the concentration, and R2 was above 0.97. This study provides a feasible strategy for developing a convenient, effective and universal ratiometric fluorescent sensor.