Abstract:

In view of the harm of leuco malachite green (LMG) to human health, it is important to establish a sensitive and rapid method for the detection of LMG residues in aquatic products. In this study, a novel molecularly imprinted electrochemical sensor (MIECS) for LMG detection was successfully prepared by the fusion of variety technologies, such as computer simulation technology, ultraviolet spectroscopy, self-assembled technique and electrochemical analysis technology. In the experiment, based on nanomaterial modified electrodes, LMG was used as the template molecule, and 4-aminophenol(4-ATP) was selected as the best functional monomer by the use of ultraviolet spectroscopy combined with computer simulation. The configuration, action forms and binding energies of the LMG and 4-ATP preassembly systems were simulated and calculated by using Gaussian 09. The morphology and chemical characterization of the membrane were characterized by scanning electron microscope and infrared spectrometer, and the imprinted effect and selection performance of the sensor were investigated by cyclic voltammetry and square-wave voltammetry. The sensor was applied for the rapid detection of food safety. The results showed that the template molecule and functional monomer mainly formed the LMG-2(4-ATP) complex through conjugation action. The sensor demonstrated good performance and could specifically recognize the LMG and its structural analogs. The linear response range of this method was 3.3×10^-11—1.0×10^-6mol/L with a good linear relationship, the detection limit was 1.0×10^-11mol/L, the spiked sample recoveries were between 85.5% and 101.2% and the relative standard deviations were 1.28%—2.48%. It was suitable for the sensitive and rapid detection of LMG residues in aquatic products. In the future, MIECS would be more sensitive, accurate, fast and miniaturized, and applied in more fields.

Key words: leuco malachite green, computer molecular simulation technology, ultraviolet spectroscopy, electrochemical analysis technology, molecularly imprinted sensor

摘要：

鉴于隐色孔雀石绿（LMG）对人体健康的危害性，建立灵敏快速检测水产品中LMG残留的方法有着重要意义。本研究将计算机模拟技术、紫外光谱技术、自组装技术及电化学分析等多种技术相融合，成功制备了用于检测LMG的分子印迹电化学传感器（MIECS）。基于纳米材料修饰电极，以LMG为模板分子，运用紫外光谱法结合计算机模拟筛选4-氨基苯硫酚（4-ATP）为最佳功能单体，通过Gaussian 09软件模拟计算LMG和4-ATP预组装体系的构型、作用形式及结合能。利用扫描电镜、红外光谱仪对其进行形貌和化学结构表征，采用循环伏安法和方波伏安法研究其印迹效果和选择性，并将其应用于食品安全快速检测。结果表明，模板分子和功能单体主要形成LMG-2(4-ATP) 型复合物，该传感器具有良好的性能，可特异性识别LMG及其结构类似物；该方法在3.3×10^-11～1.0×10^-6mol/L范围内线性关系良好，检出限为1.0×10^-11mol/L，样品加标回收率为85.5%～101.2%，相对标准偏差为1.28%～2.48%，适用于水产品中LMG残留量的灵敏快速检测。未来MIECS将向更灵敏、准确、快速及小型化和微型化方向发展，并应用于更多领域。

关键词: 隐色孔雀石绿, 计算机分子模拟技术, 紫外光谱技术, 电化学分析技术, 分子印迹传感器