西草净分子印迹电化学传感器的制备及应用

为了解决大型检测仪器在检测过程中的局限性，利用分子印迹技术，以西草净为模板分子、甲基丙烯酸为功能单体，采用原位引发聚合法，在玻碳电极表面进行热聚合成膜，制备出西草净分子印迹电化学传感器，并将其用于样品中西草净含量的检测。采用循环伏安法 (CV) 对印迹电极的电化学性能进行了测试，并使用超高效液相色谱-串联质谱法 (UPLC-MS/MS) 对测试结果进行验证。结果表明:在滴涂量为10 μL、60 ℃下热聚合制备出的西草净电化学传感器 (SMT-MIP/GCE) 具有良好的选择性、重复性和稳定性，其线性范围为0.5~1 μmol/L(1) 和2~30 μmol/L(2)，对应的线性关系分别为I₁ = ?3.33 c+39.03，I₂= ?0.75 c+35.52，相关系数分别为r₁ = 0.985，r₂ = 0.997，检出限 (LOD) 分别为LOD₁ = 0.13 μmol/L和LOD₂ = 0.89 μmol/L。将所建立的西草净分子印迹电化学检测方法用于烟叶添加样品提取液中西草净的检测，该印迹电极能够在8 min内完成对烟叶添加样品提取液中西草净的吸附，回收率为76%~88%，相对标准偏差为2.7%~7.6%，该方法能够初步满足烟草中西草净快速检测的需求。

Preparation and application of simetryn molecular imprinted electrochemical sensor

In order to solve the limitations of large-scale testing instruments for the convenient and fast detection of simetryn, the molecular imprinting electrochemical sensor of simetryn (SMT) was prepared by in-situ initiation polymerization. The film was directly thermally polymerized on the surface of glassy carbon electrodes with simetryn as template molecule and methacrylic acid was used as the functional monomer. The sensor was then applied to detect the content of simetryn in samples. The electrochemical performance of the electrochemical sensor was tested by cyclic voltammetry (CV). The test results were verified by the ultra high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results show that the electrochemical sensor prepared by thermal polymerization at a dosage of 10 μL pre-polymerization liquid and a coating temperature of 60 ℃ has good selectivity, repeatability and stability. The detection linear relationship were I₁=?3.33c+39.03 (0.5-1 μmol/L) and I₂=?0.75c+35.52 (2-30 μmol/L) respectively. The correlation coefficients were r₁ = 0.985 and r₂ = 0.997. And the detection limits (LOD) were LOD₁ = 0.13 μmol/L and LOD₂ = 0.89 μmol/L. When the molecular imprinting electrochemical method was applied to determine the content of simetryn in tobacco leaves, the imprinted electrode could complete the adsorption of simetryn in the ertact solution of spiked tobacco leaves in 8 min, with a recovery rate of 76%-88%. The relative standard deviation was 2.7%-7.6%. This method can preliminarily meet the needs of rapid detection of simetryn in tobacco.