基于纳米金/铜有机骨架的酶传感器检测蔬菜中敌敌畏

Detection of dichlorvos in vegetables based on gold nanoparticles/copper-origin frameworks enzyme sensor

目的 制备氨基化纳米金/铜有机骨架(aminated gold nanoparticles/copper-origin frameworks,AuNPs-NH_(2)/Cu-MOF)纳米复合材料,并构建新型乙酰胆碱酯酶(acetylcholinesterase,AChE)传感器对蔬菜中敌敌畏进行定量分析。方法 采用羧甲基壳聚糖(carboxymethyl chitosan,CMCS)为交联剂,AuNPs-NH_(2)/Cu-MOF为修饰材料,玻碳电极(glassy carbon electrode,GCE)为工作电极,构建AChE/AuNPs-NH_(2)/Cu-MOF/GCE传感器。通过对交联剂、酶固载量、抑制时间的优化,确定传感器的最佳工作条件,对蔬菜中敌敌畏进行检测分析。结果 AuNPs-NH_(2)/Cu-MOF不仅具有良好的导电性和生物相容性,还可以为酶和底物提供更多的接触位点,有效地提高传感器的灵敏度。在最佳工作条件下,在1.0×10^(10)~1.0×10^(-5)g/L之间,敌敌畏浓度的负对数与其对传感器的抑制率呈线性关系,检出限出1.7951×10;g/L(按抑制率10%计算)。加标回收率在96.28%~103.20%之间,检测结果与高效液相色谱法检测结果一致,且该传感器重复性、稳定性较好,对常见的Pb^(2+)、Zn^(2+)、Ni^(2+)和Cd;有良好的抗干扰能力。结论 AChE/AuNPs-NH_(2)/Cu-MOF/GCE传感器操作简便、快捷,可用于蔬菜中敌敌畏的快速定量分析。

Objective To prepare aminated gold nanoparticles/copper-origin frameworks (AuNPs-NH_(2)/Cu-MOF) nanocomposites,and construct a new acetylcholinesterase (AChE) sensor for the detection of dichlorvos in vegetables.Methods AChE/AuNPs-NH_(2)/Cu-MOF/GCE sensor was constructed using carboxymethyl chitosan (CMCS)as crosslinking agent,AuNPs-NH_(2)/Cu-MOF as modified material,and glassy carbon electrode (GCE) as working electrode.The optimum working conditions of the sensor were determined by optimizing crosslinking agent,enzyme immobilization,inhibition time to detect and analyze dichlorvos in vegetables.Results AuNPs-NH_(2)/Cu-MOF not only had good conductivity and biocompatibility,but also could provide more contact sites for enzymes and substrates,which could effectively improve the sensitivity of the sensor.Under the optimum conditions,the negative logarithm of dichlorvos concentration showed a good linear relationship with its inhibition rate to the sensor in the range of 1.0×10^(10)~1.0×10^(-5)g/L,the limit of detection was 1.7951×10;g/L (calculated according to the inhibition rate of 10%).The recoveries were 96.28%-103.20%,the detection results were consistent with the result of high performance liquid chromatography,and the sensor had good repeatability and stability,and good anti-interference ability to common Pb^(2+)、Zn^(2+)、Ni^(2+)and Cd;.Conclusion AChE/AuNPs-NH_(2)/Cu-MOF/GCE is easy to operate and rapid,and can be used for detecting dichlorvos in vegetables rapidly.