The State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo, China.
Toxins (Basel). 2013 Apr 29;5(5):865-83. doi: 10.3390/toxins5050865.
An ultrasensitive electrochemiluminescent immunoassay (ECLIA) for aflatoxins M1 (ATM1) in milk using magnetic Fe3O4-graphene oxides (Fe-GO) as the absorbent and antibody-labeled cadmium telluride quantum dots (CdTe QDs) as the signal tag is presented. Firstly, Fe3O4 nanoparticles were immobilized on GO to fabricate the magnetic nanocomposites, which were used as absorbent to ATM1. Secondly, aflatoxin M1 antibody (primary antibody, ATM1 Ab1), was attached to the surface of the CdTe QDs-carbon nanotubes nanocomposite to form the signal tag (ATM1 Ab1/CdTe-CNT). The above materials were characterized. The optimal experimental conditions were obtained. Thirdly, Fe-GO was employed for extraction of ATM1 in milk. Results indicated that it can adsorb ATM1 efficiently and selectively within a large extent of pH from 3.0 to 8.0. Adsorption processes reached 95% of the equilibrium within 10 min. Lastly, the ATM1 with a serial of concentrations absorbed on Fe-GO was conjugated with ATM1 Ab1/CdTe-CNT signal tag based on sandwich immunoassay. The immunocomplex can emit a strong ECL signal whose intensity depended linearly on the logarithm of ATM1 concentration from 1.0 to 1.0 × 10(5) pg/mL, with the detection limit (LOD) of 0.3 pg/mL (S/N = 3). The method was more sensitive for ATM1 detection compared to the ELISA method. Finally, ten samples of milk were tested based on the immunoassay. The method is fast and requires very little sample preparation, which was suitable for high-throughput screening of mycotoxins in food.
本文提出了一种基于超灵敏电化学发光免疫分析（ECLIA）的牛奶中黄曲霉毒素 M1（ATM1）检测方法，该方法使用磁性 Fe3O4-氧化石墨烯（Fe-GO）作为吸附剂，抗体标记的碲化镉量子点（CdTe QDs）作为信号标记物。首先，将 Fe3O4 纳米粒子固定在 GO 上，制备磁性纳米复合材料，将其用作 ATM1 的吸附剂。其次，将黄曲霉毒素 M1 抗体（一级抗体，ATM1 Ab1）连接到 CdTe QDs-碳纳米管纳米复合材料的表面上，形成信号标记物（ATM1 Ab1/CdTe-CNT）。对上述材料进行了表征，并得到了最佳的实验条件。然后，使用 Fe-GO 从 pH 值为 3.0 到 8.0 的范围内从牛奶中提取 ATM1。结果表明，它可以在很大的 pH 范围内高效且选择性地吸附 ATM1。吸附过程在 10 min 内达到 95%的平衡。最后，将一系列浓度的 ATM1 吸附在 Fe-GO 上，然后与 ATM1 Ab1/CdTe-CNT 信号标记物基于夹心免疫测定法进行偶联。免疫复合物会发出强的 ECL 信号，其强度与 ATM1 浓度的对数呈线性关系，从 1.0 到 1.0×10(5)pg/mL，检测限（LOD）为 0.3 pg/mL（S/N = 3）。与 ELISA 方法相比，该方法对 ATM1 的检测更为敏感。最后，基于免疫测定法对 10 份牛奶样品进行了测试。该方法快速且需要很少的样品制备，适用于食品中真菌毒素的高通量筛选。
