基于ZIF-8@Ag/MWCNTs的绿原酸电化学传感器的构建及应用

构建了用于定量分析绿原酸的ZIF-8@Ag/MWCNTs电化学传感器。Ag纳米粒子具有良好的导电性和电催化能力，而ZIF-8优秀的比表面积能有效的分散Ag纳米粒子，因此在室温合成ZIF-8后，在ZIF-8表面原位还原Ag+制备ZIF-8@Ag复合材料。然后，以MWCNTs作为基底材料，复合ZIF-8@Ag获得修饰工作电极，获得高灵敏度的电化学传感器用于绿原酸的测定。通过循环伏安法（CV）、电化学阻抗谱（EIS）和差分脉冲伏安法（DPV），探讨了ZIF-8@Ag/MWCNTs/GCE的电化学传感性能。在优化的实验条件下，绿原酸标准品浓度在5×10-8 mol/L~1×10-5 mol/L范围内与氧化峰电流具有良好的线性关系，检出限为1.36×10-8 mol/L（S/N=3）。探究了修饰电极的抗干扰性、重复性和再现性，结果表明电极抗干扰能力较强，重复性及再现性表现良好。用于实际样品绿咖啡豆稀释液的检测时，加标回收率在96.34%~103.34%。该方法简便、可靠，可用于绿原酸及绿原酸实际样品的快速定量分析。

Construction and Application of Chlorogenic Acid Electrochemical Sensor Based on ZIF-8@Ag/MWCNTs

ZIF-8@Ag/MWCNTs electrochemical sensors were prepared and used for the quantitative analysis of chlorogenic acid. Ag nanoparticles have good electrical conductivity and electrocatalytic ability, and they can be effectively dispersed by the excellent specific surface area of ZIF-8. Therefore, ZIF-8@Ag nanocomposites were prepared by Ag+ in-situ reduction on the surface of ZIF-8 after ZIF-8 was synthesized at room temperature. Then, MWCNTs was used as the substrate and compounded with ZIF-8@Ag to form a modified working electrode, a highly sensitive electrochemical sensor was obtained for the analysis of chlorogenic acid. The electrochemically sensing capability of ZIF-8@Ag/MWCNTs/GCE was explored via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) techniques. Under the optimized experimental conditions, the standard substance concentration of chlorogenic acid had a good linear relationship with oxidation peak current in the range of 5×10-8 mol/L~1×10-5 mol/L. The detection limit can be as low as 1.36×10-8 mol/L (S/N=3). The anti-interference ability, repeatability, and reproducibility of the modified electrode were investigated, and the results showed that the electrode had a strong anti-interference ability, and performed well in repeatability and reproducibility. When it is used for the detection of the actual sample green coffee bean diluent, the recovery rate was between 96.34%~103.34%. The method is simple and reliable, and can be used for rapid quantitative analysis of chlorogenic acid and actual samples of chlorogenic acid.