School of Chemistry and Chemical Engineering, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, China.
CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Talanta. 2024 Jun 1;273:125874. doi: 10.1016/j.talanta.2024.125874. Epub 2024 Mar 4.
2-Methyl-4-chlorophenoxyacetic acid (MCPA) is one of the most widely used herbicides, so adsorption and detection of MCPA in the environment is critical. Blue fluorescent carbon dot (CD) was synthesized from citric acid and urea, which could be quenched by MCPA. Herein, bifunctional molecularly imprinted polymer (CD@MIP) was prepared on monodisperse poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres, with 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linking agent, and doped with CD. The enrichment ability of CD@MIP for MCPA and fluorescence detection performance were determined. The maximum adsorption amount of MCPA was 93.9 mg g as determined by isothermal adsorption experiments and was in accordance with the Langmuir adsorption model. The results of the kinetic experiments showed that the adsorption equilibrium reached within 30 min, which possessed a relatively fast adsorption rate and was in accordance with the pseudo-second-order adsorption model. Both MIP without CD and non-imprinted polymers were also fabricated and tested as references. Fluorescence experiments showed good linearity of CD@MIP in the range of 0-80 μmol. The cabbage samples were analyzed by high performance liquid chromatography with a linear range of 0.02-15 μg mL, recoveries of 90.5%-98% and low relative standard deviations (RSD, n = 3) of 1.5%-5.9%. CD@MIP with excellent performance provides a feasible practical application in the detection and enrichment of MCPA.
2-甲基-4-氯苯氧乙酸（MCPA）是应用最广泛的除草剂之一，因此对其在环境中的吸附和检测至关重要。本文以柠檬酸和尿素为原料合成了发蓝色荧光的碳点（CD），MCPA 可使 CD 荧光猝灭。在此基础上，以单分散的聚（甲基丙烯酸缩水甘油酯-co-乙二醇二甲基丙烯酸酯）微球为载体，以 4-乙烯基吡啶为功能单体、乙二醇二甲基丙烯酸酯为交联剂，制备了双功能分子印迹聚合物（CD@MIP），并掺杂了 CD。研究了 CD@MIP 对 MCPA 的富集能力和荧光检测性能。通过等温吸附实验确定 MCPA 的最大吸附量为 93.9mg·g，符合朗缪尔吸附模型。动力学实验结果表明，吸附平衡在 30min 内达到，具有较快的吸附速率，符合准二级吸附模型。同时还制备了不含 CD 的 MIP 和非印迹聚合物作为对照进行测试。荧光实验表明，CD@MIP 在 0-80μmol 范围内具有良好的线性关系。采用高效液相色谱法对白菜样品进行分析，线性范围为 0.02-15μg·mL，回收率为 90.5%-98%，相对标准偏差（RSD，n=3）为 1.5%-5.9%。具有优异性能的 CD@MIP 为 MCPA 的检测和富集提供了一种可行的实际应用。
