基于苯醚甲环唑分子印迹的电化学传感器研究

发布时间：2018-08-14 11:50

【摘要】：苯醚甲环唑是一种被广泛使用的低毒性杀菌剂。目前,用于检测食品中苯醚甲环唑的方法主要有液相色谱法,气相色谱法,色谱-质谱联用等分析方法。然而,这些方法均有一些缺点,如:检测耗费时间长,所需仪器昂贵,在检测过程中需要耗费大量的溶剂等。因此,建立一种快速、灵敏的苯醚甲环唑检测方法具有重要意义。本研究建立了一种基于金纳米颗粒及分子印迹的电化学传感检测方法,用于食品中苯醚甲环唑的检测。具体方法是,以苯醚甲环唑为模板分子,对氨基苯硫酚为功能单体,在修饰有金纳米颗粒的玻碳电极表面电沉积分子印迹聚合物膜,从而实现对苯醚甲环唑的特异性检测。一方面,金纳米颗粒可以作为增强电化学传感器的电信号材料,增大电极比表面积从而提高电极表面分子印迹聚合物膜的有效印迹位点;另一方面,修饰的分子印迹聚合物膜可特异性识别目标物苯醚甲环唑。在实验中,使用扫描电子显微镜,原子力显微镜对修饰有金纳米颗粒及金纳米颗粒-分子印迹膜的玻碳电极进行形貌表征,同时用循环伏安法以及差分脉冲伏安法对工作电极进行条件优化及电化学行为表征。最后,对构建传感器的吸附性,选择性,重复性,稳定性进行评价及分析。结果表明,在优化的条件下,构建的电化学传感器在2×10-6-1.4×10-5molL-1浓度范围内对苯醚甲环唑呈现较好的电化学响应,根据三倍信噪比(S/N=3)计算,该方法的最低检出限为9.49×10-7molL-1。此外,构建的电化学传感器有良好的选择性、重复性和稳定性。该方法成功地用于食品(白菜,苹果,桃汁)中苯醚甲环唑的加标回收检测,用高效液相色谱法验证,两种方法具有一致性。综上所述,这种电化学传感器能够为检测食品中的苯醚甲环唑提供一种新方法。
[Abstract]:Difenoconazole is a widely used fungicides with low toxicity. At present, liquid chromatography, gas chromatography, chromatography-mass spectrometry and other analytical methods are the main methods for the determination of dimethyclozole in food. However, these methods have some disadvantages, such as: the detection takes a long time, the required instruments are expensive, and a large amount of solvents are needed in the detection process. Therefore, it is of great significance to establish a rapid and sensitive method for the determination of dimethylcyclozole. An electrochemical sensing method based on gold nanoparticles and molecular imprinting was developed for the detection of diphenyl ether triazole in food. The specific method is to electrodeposit molecularly imprinted polymer films on the surface of glassy carbon electrode modified with gold nanoparticles using diphenyl ether dioxazole as template molecule and p aminophenol as functional monomer. On the one hand, gold nanoparticles can be used as electrical signal materials to enhance the electrochemical sensor, increase the specific surface area of the electrode and thus improve the effective imprinting site of the molecularly imprinted polymer membrane on the electrode surface. The modified molecularly imprinted polymer membrane can specifically recognize the target of diphenyl ether triazole. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the morphology of glassy carbon electrodes modified with gold nanoparticles and molecularly imprinted films. The working electrode was optimized by cyclic voltammetry and differential pulse voltammetry. Finally, the adsorbability, selectivity, repeatability and stability of the sensor were evaluated and analyzed. The results show that the electrochemical sensor has a good electrochemical response to diphenyl ether triazole in the concentration range of 2 脳 10 ~ (-6) to 1.4 脳 10-5molL-1, and the detection limit of the method is 9.49 脳 10 ~ (-7) mol / L ~ (-1), calculated according to the triple signal-to-noise ratio (S/N=3). In addition, the electrochemical sensor has good selectivity, repeatability and stability. The method has been successfully applied to the determination of dioxazole in food (cabbage, apple and peach juice). The two methods are consistent with each other by high performance liquid chromatography (HPLC). In conclusion, this electrochemical sensor can provide a new method for the detection of diphenyl ether triazole in food.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS207.5;TP212.2

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