基于核酸适配体与DNA长距自组装的电化学传感器定量检测赭曲霉毒素A

Quantitative detection of ochratoxin A based on aptamer and DNA long-range self-assembly electrochemical sensor

中文关键词:  赭曲霉毒素A  核酸适配体  DNA自组装  电化学传感器

英文关键词:ochratoxin A  aptamer  DNA self-assembly  electrochemical sensor

中文摘要:

      目的 开发一种基于核酸适配体与DNA长距自组装的电化学传感器用于赭曲霉毒素A (Ochratoxin A，OTA)的快速、灵敏检测。方法 在磁珠表面修饰核酸适配体，利用其特异性识别OTA，并释放引物链 (primer)。通过磁性分离将引物链分离出来，并利用电极界面的捕获探针捕获引物链，从而引发两条辅助探针的级联杂交，形成长距DNA自组装结构。该结构的负电荷骨架可吸附大量带有正电荷的电活性分子亚甲基蓝 (Methylene blue，MB)，产生显著的电化学信号，从而实现OTA的灵敏检测。结果 传感器具有良好的特异性和稳定性，在最佳条件下，传感器的线性范围为0.012~0.12 pg/mL，相关系数为0.99158，检测限为0.6 fg/mL。结论 基于核酸适配体与DNA长距自组装技术，构建了一种用于OTA简单、快速、准确、灵敏检测的电化学传感器，为食品中OTA的灵敏检测提供了新的视角。

英文摘要:

      Objective Development of an electrochemical sensor based on aptamer and DNA long-range self-assembly for the rapid and sensitive detection of the ochratoxin A (OTA). Methods The aptamer was modified on the surface of the magnetic beads, which specifically recognized OTA and released the primer. The primer was then separated by magnetic separation, and was captured by the capture probe at the electrode interface, which triggers the cascade hybridization of two auxiliary probes to form a long-distance DNA self-assembly structure. The negative charge skeleton of the structure can adsorb a large number of positively charged electroactive molecules Methylene blue (MB), resulting in a significant electrochemical signal, thereby achieving sensitive detection of OTA. Results The sensor had good specificity and stability. Under the optimal conditions, the linear range of the sensor was 0.012-0.12 pg/mL, the correlation coefficient was 0.99158, and the detection limit was 0.6 fg/mL. Conclusion Based on the long-range self-assembly technology of aptamer and DNA, an electrochemical sensor for simple, rapid, accurate and sensitive detection of OTA was constructed, which provided a new perspective for the sensitive detection of OTA in food.