基于金掺杂的锆基金属有机框架电化学适配体传感器检测玉米中黄曲霉毒素B1

Detection of aflatoxin B1 in maize based on gold-doped zirconium-based metal-organic framework electrochemical aptamer sensor

中文关键词:  黄曲霉毒素B1(AFB1)  金掺杂的锆基金属有机框架  适配体  阻抗型传感器

英文关键词:aflatoxin B1  gold-doped zirconium-based metal-organic frameworks  aptamer  impedance type sensor  maize

中文摘要:

      目的 建立基于金掺杂的锆基金属有机框架(gold-doped zirconium-based metal-organic framework, Au@Zr-MOF)的电化学适配体传感器检测玉米中黄曲霉毒素B1 (aflatoxin B1, AFB1)的方法。方法 利用具有高比表面积、介孔结构的Zr-MOF作为骨架, 通过原位还原生长的方法掺杂金纳米粒子, 得到导电性良好、分散均匀的Au@Zr-MOF。并基于Au-S键共价结合AFB1适配体, 构建电化学阻抗型适配体传感器, 当AFB1存在时, 适配体对其进行识别结合, 引起电极表面电化学传质电阻增加, 随着AFB1浓度的增大, 阻抗值也随之增加, 并根据阻抗值的变化实现对AFB1的定量检测。结果 在最佳的实验条件下, 该传感器对AFB1检测的线性范围为10?4~101 ng/mL, 检出限为0.19 pg/mL, 对玉米样品的回收率为96%~112%。结论 本研究建立的电化学适配体传感器可以实现对AFB1的定量检测, 且具有良好的特异性和重现性, 为准确、快速检测食品中的AFB1提供思路。

英文摘要:

      Objective To establish a method for detecting aflatoxins B1 (AFB1) in maize by electrochemical aptamer sensor based on gold-doped zirconium-based metal-organic framework (Au@Zr-MOF). Methods Zr-MOF with high specific surface area and mesoporous structure was used as a backbone to obtain Au@Zr-MOF with good conductivity and uniform dispersion by in situ reductive growth method. An electrochemical impedance aptamer was constructed based on Au-S bond covalently binding AFB1 aptamer. When AFB1 was present, the aptamer recognized and bound to it, causing an increase in electrochemical mass transfer resistance on the electrode surface, and as the concentration of AFB1 increases, the impedance value also increased, and the quantitative detection of AFB1 was achieved according to the change of impedance value. Results Under the optimal experimental conditions, the linear range of AFB1 detection was 10?4?101 ng/mL, the limit of detection was 0.19 pg/mL, and the recoveries of maize samples were 96%?112%. Conclusion The electrochemical aptamer sensor established in this study can realize the quantitative detection of AFB1 with good specificity and reproducibility, which provides ideas for accurate and rapid detection of AFB1 in food.