Ochratoxin A (OTA) is a common food contaminant and poses a significant threat to human health, which requires rigorous monitoring. Mimotope peptides (MPs) are commonly used as non-toxic alternatives to toxic small molecules in eco-friendly immunoassays. Herein, with an anti-OTA nanobody as the target protein, cyclic 7-mer MPs of OTA were screened using phage display and immunomagnetic separation. The phage MPs (PMP) with the highest sensitivity and its alkaline phosphatase-tagged MP fusion (ALP-MP) were used to develop a PMP-based chemiluminescent immunoassay (PMP-CLIA) and an ALP-MP-based CLIA (AMP-CLIA). After optimization, PMP-CLIA and AMP-CLIA exhibited a limit of detection of 0.128 ng/mL and 0.232 ng/mL. Good accuracy and selectivity were confirmed for both CLIAs by recovery experiments and cross-reactions. Moreover, they were validated by high performance liquid chromatography in detecting real pepper samples. Thus, two CLIAs based on the nanobody and MPs were demonstrated as reliable tools for monitoring OTA in pepper.

中文翻译：

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用于纳米抗体的 Mimotope 肽：赭曲霉毒素 A 的无毒替代品及其在辣椒样品分析的化学发光免疫测定中的应用


赭曲霉毒素 A （OTA） 是一种常见的食品污染物，对人类健康构成重大威胁，需要严格监测。在环保免疫测定中，Mimotope 肽 （MP） 通常用作有毒小分子的无毒替代品。在此，以抗 OTA 纳米抗体为靶蛋白，使用噬菌体展示和免疫磁性分离筛选 OTA 的环状 7 聚体 MP。使用灵敏度最高的噬菌体 MPs （PMP） 及其碱性磷酸酶标记的 MP 融合 （ALP-MP） 开发基于 PMP 的化学发光免疫测定 （PMP-CLIA） 和基于 ALP-MP 的 CLIA （AMP-CLIA）。优化后，PMP-CLIA 和 AMP-CLIA 的检测限分别为 0.128 ng/mL 和 0.232 ng/mL。通过回收实验和交叉反应证实了两种 CLIA 的良好准确性和选择性。此外，它们通过高效液相色谱法检测真正的辣椒样品进行了验证。因此，基于纳米抗体和 MP 的两种 CLIA 被证明是监测辣椒中 OTA 的可靠工具。