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Abstract：
A novel electrochemical aptasensor was prepared for the simultaneous determination of aflatoxin B1 (AFB1) and ochratoxin A (OTA). Composites of Au nanoparticles and polyethyleneimine-reduced graphene oxide (AuNPs/PEI-RGO) with good electrical conductivity and high specific surface area were employed as the supporting substrate, demonstrating the ability to provide more binding sites for aptamers and accelerate the electron transfer. Aptamers were immobilized on a AuNPs/PEI-RGO surface to specifically recognize AFB1 and OTA. A metal-organic framework of UiO-66-NH2 served as the signal carrier to load metal ions of Cu2+ and Pb2+, which facilitated the generation of independent current peaks and effectively improved the electrochemical signals. The prepared aptasensor exhibited sensitive current responses for AFB1 and OTA with a linear range of 0.01 to 1000 ng/mL, with detection limits of 6.2 ng/L for AFB1 and 3.7 ng/L for OTA, respectively. The aptasensor was applied to detect AFB1 and OTA in cereal samples, achieving results comparable with HPLC-MS, with recovery results from 92.5% to 104.1%. With these merits of high sensitivity and good selectivity and stability, the prepared aptasensor proved to be a powerful tool for evaluating contaminated cereals.
摘要：
制备了一种新型的电化学传感器，用于同时测定黄曲霉毒素B1（AFB1）和曲霉毒素A（OTA）。采用具有良好导电性和高比表面积的Au纳米颗粒和聚乙烯亚胺还原的氧化石墨烯（AuNP/PEI-RGO）的复合材料作为支撑基底，证明了为适体提供更多结合位点并加速电子转移的能力。将适体固定在AuNP/PEI-RGO表面上以特异性识别AFB1和OTA。UiO-66-NH2的金属有机骨架充当信号载体，负载Cu2和Pb2的金属离子，这促进了独立电流峰的产生，有效地改善了电化学信号。制备的aptasensor对AFB1和OTA表现出灵敏的电流响应，线性范围为0.01至1000ng/mL，AFB1的检测限为6.2ng/L，OTA的检测限为3.7ng/L，分别。应用aptasensor检测谷物样品中的AFB1和OTA，达到与HPLC-MS相当的结果，回收率为92.5%～104.1%。具有灵敏度高、选择性和稳定性好等优点,准备好的aptasensor被证明是评估受污染谷物的有力工具。
