National Reference Laboratory of Veterinary Drug Residues (HZAU), Huazhong Agricultural University, Wuhan 430070, China.
Key Laboratory of the Detection for Veterinary Drug Residues, Ministry of Agriculture, Wuhan 430070, China.
Int J Mol Sci. 2018 Dec 5;19(12):3895. doi: 10.3390/ijms19123895.
T-2 toxin (T-2) is one of major concern mycotoxins acknowledged as an unavoidable contaminant in human foods, animal feeds and also agriculture products. Thus, a facile and sensitive method is essential for accurate T-2 toxin detection. In our work, a specific electrochemical immunosensor based on gold nanoparticles/carboxylic group-functionalized single-walled carbon nanotubes/chitosan (AuNPs/cSWNTs/CS) composite was established. The mechanism of the electrochemical immunosensor was an indirect competitive binding to a given amount of anti-T-2 between free T-2 and T-2-bovine serum albumin, which was conjugated on covalently functionalized cSWNTs decorated on the glass carbon electrode. Afterwards, the alkaline phosphatase labeled anti-mouse secondary antibody was bound to the electrode surface by reacting with the primary antibody. Lastly, alkaline phosphatase catalyzed the hydrolysis of the substrate α-naphthyl phosphate, which produced an electrochemical signal. Compared with conventional methods, the established immunosensor was more sensitive and simpler. Under optimal conditions, this method could quantitatively detect T-2 from 0.01 to 100 μg·L with a detection limit of 0.13 μg·L and favorable recovery 91.42⁻102.49%. Moreover, the immunosensor was successfully applied to assay T-2 in feed and swine meat, which showed good correlation with the results obtained from liquid chromatography-tandem mass spectrometry (LC-MS/MS).
T-2 毒素（T-2）是一种主要的真菌毒素，被认为是人类食品、动物饲料和农产品中不可避免的污染物。因此，需要一种简单、灵敏的方法来准确检测 T-2 毒素。在我们的工作中，建立了基于金纳米粒子/羧基功能化单壁碳纳米管/壳聚糖（AuNPs/cSWNTs/CS）复合材料的特定电化学免疫传感器。电化学免疫传感器的机制是基于给定数量的游离 T-2 与 T-2-牛血清白蛋白之间的间接竞争结合，T-2-牛血清白蛋白结合在共价功能化的 cSWNTs 上，后者修饰在玻碳电极上。然后，碱性磷酸酶标记的抗鼠二抗通过与抗体反应结合到电极表面。最后，碱性磷酸酶催化底物α-萘基磷酸的水解，产生电化学信号。与传统方法相比，建立的免疫传感器更灵敏、更简单。在最佳条件下，该方法可以从 0.01 到 100μg·L 定量检测 T-2，检测限为 0.13μg·L，回收率为 91.42⁻102.49%。此外，该免疫传感器成功地应用于饲料和猪肉中 T-2 的测定，与液相色谱-串联质谱（LC-MS/MS）得到的结果具有良好的相关性。
