基于适配体修饰纳米酶的赭曲霉毒素A快速检测试纸条的研制

Foods, especially agricultural products, are susceptible to ochratoxin A (OTA), which is highly toxic, widespread and productive. Therefore, fast and sensitive in situ detection of OTA plays an important role in ensuring food safety. Currently, most of the test strip for in situ detection is based on gold-labeled immunoassay. Unfortunately, these test-strips have the common problems of immune method, such as high cost, poor stability, poor immunity and false positive. This project aimed at the construction of a novel test-strip aptasensor for visual, rapid and sensitive detection of OTA by using DNA aptamers with high affinity, high stability, easy modification and other excellent features as recognition element, and amplifying signal through combining the catalytic properties of nanozymes with the enrichment of test strip. The aptasensor to construct has the advantage of visual, portable, easy operation and low cost. By using aptasensor as recognition element, the test-strip can be extended to detect wider range of targets. The constructed test strip biosensor is promising for monitoring, processing, risk assessment and early warming of fungaltoxin.

赭曲霉毒素A（OTA）毒性大、分布广、产毒量高，食品特别是农产品极易受其污染。因此，对食品中OTA进行现场、快速、高灵敏检测在确保人民饮食安全方面具有重要意义。目前用于现场检测的试纸条多数是金标免疫法。这类试纸条具有免疫方法的通病，例如：成本高、稳定性差、免疫性差、假阳性等。本研究拟以具有高亲和性、高稳定性、易修饰等优良特性的DNA适配体为识别元件，同时将纳米酶的催化性能与试纸条的富集作用相结合进行信号放大，建立可视化试纸条适配体传感器用于食品中OTA的快速、高灵敏、高特异性检测。所要构建的试纸条传感器具有信号可视、便携、操作简单、成本低等优点。以适配体为识别元件，使试纸条的检测目标物更为广泛。所构建的试纸条传感器有望为食品中真菌毒素监测处理、风险评价及预警提供技术支持。

发展新型纳米酶用于食品中赭曲霉毒素A的快速检测具有重要意义。本文以合成具有高催化活性的纳米酶，实现食品中赭曲霉毒素A快速检测为目标，合成和研究了几种纳米酶及其在食品安全检测方面的应用，还构建了一种赭曲霉毒素A检测方法。具体研究内容包括：（1）研制了一种具有氧化酶活性的g-C3N4-Pt纳米粒子，用于Hg2+的快速可视化检测。（2）研制了一种具有过氧化物酶活性的g-C3N4-Au纳米粒子，用于Hg2+的快速可视化检测。（3）研制了一种具有过氧化物酶活性的Pt纳米粒子，用于Ag+的快速可视化检测。（4）研制了一种通用型的基于铜离子介导量子点原位合成的免疫传感方法，用于甲胎蛋白的检测。（5）研制了一种基于金属有机框架结构的电化学赭曲霉毒素A传感方法。