Fe3O4@Au-Cu/金属有机框架纳米酶电化学传感器检测食品中亚硝酸盐

Fe3O4@Au-Cu/metal organic framework nanozyme electrochemical sensor for the detection of nitrite in food

中文关键词:  金属有机框架  亚硝酸盐  模拟酶  电化学生物传感器  食品分析

英文关键词:metal organic framework  nitrite  mimic enzyme  electrochemical biosensor  food analysis

中文摘要:

      目的 基于类酶活性的自组装材料构建Fe3O4@Au-Cu/金属有机框架(Fe3O4@Au-Cu/metal organic framework, Fe3O4@Au-Cu/MOF)实现食品中亚硝酸盐的检测。方法 采用透射电子显微镜和傅里叶红外光谱对合成的Fe3O4@Au-Cu/MOF进行表征。利用循环伏安法, 通过改变Fe3O4@Au-Cu/MOF添加量、温度、扫描速率以及pH进行单因素和正交实验。根据最优体系对1~100 mmol/L的亚硝酸盐进行检测, 绘制工作曲线, 进行抗干扰实验和实际样品检测。结果 合成的Fe3O4@Au-Cu/MOF具有催化活性高、暴露活性位点多和孔隙率高等优势。当Fe3O4@Au-Cu/MOF添加量为0.0075 g, 温度为40℃, 扫描速率为0.08 V/s, pH为7时为最优检测体系。工作曲线为Y=0.36118X+15.57962, r2=0.99603, 检出限为1.6 μmol/L, 具有较强的抗干扰性。在实际样品检测中, 回收率为99.1%~108.2%, 相对标准偏差小于4.00%。结论 与现有方法相比, 合成的Fe3O4@Au-Cu/MOF催化H2O2产生氧化活性物质, 促进亚硝酸盐氧化, 增加体系中电荷移动的能力更强。该方法构建的电化学传感器具有可靠、方便、灵敏和成本低等特点, 为食品中亚硝酸盐的检测提供了一种新的思路。

英文摘要:

      Objective To construct a Fe3O4@Au-Cu/meal organic framework (Fe3O4@Au-Cu/MOF) based on enzyme-like self-assembly materials with enzyme-like activity for the detection of nitrite in food. Methods The synthesized Fe3O4@Au-Cu/MOF was characterized by a transmission electron microscope and Fourier transform infrared spectrometer. Cyclic voltammetry by varying Fe3O4@Au-Cu/MOF addition, temperature, scan rate, and pH was used to perform single-factor and orthogonal experiments. According to the optimal system obtained by the orthogonal test, the nitrite concentration of 1?100 mmol/L was detected and the working curve was drawn. Finally, the established system was used for anti-interference and actual sample detection. Results The synthesized Fe3O4@Au-Cu/MOF had high catalytic activity, a large number of exposed active sites and high porosity. When the additional amount of Fe3O4@Au-Cu/MOF was 0.0075 g, the temperature was 40℃, the scanning rate was 0.08 V/s, and the pH was 7, the optimal system were detected. The regression equation of the working curve was Y=0.36118X+15.57962, r2=0.99603, the limit of detection was 1.6 μmol/L, it had a strong anti-interference ability and could be applied to actual sample detection. The recovery rates were 99.1%?108.2%, and the relative standard deviations were less than 4.00%. Conclusion Compared with the existing methods, the synthesized Fe3O4@Au- Cu/MOF is more capable of catalyzing hydrogen peroxide to produce oxidizing active substances, promote nitrite oxidation, and increase charge movement in the system. The electrochemical sensor constructed by this method has the characteristics of reliability, convenience, sensitivity and low cost, which provides a new idea for the detection of nitrite in food.