Coll Food Sci & Light Ind, Nanjing Tech University, Nanjing 211816, China.
Coll Food Sci & Light Ind, Nanjing Tech University, Nanjing 211816, China.
Food Chem. 2020 Nov 30;331:127368. doi: 10.1016/j.foodchem.2020.127368. Epub 2020 Jun 16.
A novel strategy for AFB1 detection in grains was proposed based on DNA tetrahedron-structured probe (DTP) and horseradish peroxidase (HRP) triggered polyaniline (PANI) deposition. Briefly, the DNA tetrahedron nanostructures were assembled on the gold electrode, with carboxylic group designed on top vertex of them. The carboxylic group was conjugated with the AFB1 monoclonal antibody (mAb) to form DTP. The test sample and a known fixed concentration of HRP-labeled AFB1 were mixed and they compete for binding to DTP. The HRP assembled on the gold electrode catalyzed the polymerization of aniline on DTP. AFB1 in grains could be determined by using PANI as electrochemical signal molecules. Interestingly, DNA tetrahedron-structure, which has mechanical rigidity and structural stability, can improve antigen-antibody specific recognition and binding efficiency through the use of mAb ordered assembly. Meanwhile, nucleic acid backbone with a large amount of negative charge is good template for aniline polymerization under mild conditions.
提出了一种基于 DNA 四面体结构探针（DTP）和辣根过氧化物酶（HRP）触发聚邻苯二胺（PANI）沉积的谷物中 AFB1 检测新策略。简要地说，DNA 四面体纳米结构被组装在金电极上，在它们的顶端顶点设计了羧酸基团。羧酸基团与 AFB1 单克隆抗体（mAb）缀合形成 DTP。测试样品和已知固定浓度的 HRP 标记的 AFB1 混合，它们竞争与 DTP 结合。组装在金电极上的 HRP 催化 DTP 上苯胺的聚合。通过使用 PANI 作为电化学信号分子，可以测定谷物中的 AFB1。有趣的是，具有机械刚性和结构稳定性的 DNA 四面体结构可以通过 mAb 的有序组装来提高抗原-抗体的特异性识别和结合效率。同时，带大量负电荷的核酸骨架是在温和条件下聚合苯胺的良好模板。
