食品中环境内分泌干扰物检测的低场核磁共振生物传感技术研究

In recent years, the hazard and abuse of a variety of endocrine disrupting chemicals ( EDCs ) in food has gotten more and more attention all over the world ,and then it is short of novel rapid detecting technologies on EDCs, So the object is focused on typical EDCs such as diethylstilbestrol(DES ) , 17-β-Estradiol ( E2 ) , bisphenol A(BPA) , etc. and ready to establish a new target-induced-structure-switching-dissociation systematic evolution of ligands by exponential enrichment technology for the preparation of high-affinity functionalized aptamer by discrepant and enrichment screening. Continuous studies of affinity mechanism for inter-molecular interaction between EDCs and their corresponding high-affinity aptamers are carried out employing microscale thermophoresis (MST) technology, the affinity and specificity are further improved. Then, via the optimization the reactive conditions of low field nuclear magnetic resonance (LF-NMR) detection system, LF-NMR technology based on high-affinity functionalized aptamer and nano-materials for the trace and quantitative detection of EDCs is established and the miniature intelligent LF-NMR biosensors is developed. Based on the above, further improve the performance of EDCs detecting sensitivity, specificity, detection range, etc. We combined the aptamer and LF-NMR to establish a detection technology with high affinity, good specificity via the detection of the typical model target–EDCs and achieve LF-NMR biosensor. It is advanced interdisciplinary studies on the series of novel technologies of Preventive medicine,Biology,Physics.These series of novel technologies will be applied in the fields of environmental pollution and risk of food safety assessment and control, and entry-exit inspection and quarantine, etc.,with theoretical significances and practical prospects, broader the development for hygienic analytical chemistry and related areas of novel detection technologies.

近年来，食品中多种小分子环境内分泌干扰物（EDCs）的危害及滥用越来越得到全世界的高度关注，本课题针对国内外EDCs快速检测新技术缺乏的现状，以污染食品中典型EDCs（己烯雌酚、雌二醇、双酚A等）为研究靶标，建立以新型纳米磁性材料为介质的靶标诱导变构解离-指数扩增配体系统进化技术，开展EDCs的核酸适配体的差异和富集筛选；采用微量热泳动技术开展 EDCs 与其高亲和力核酸适配体分子间相互作用分析和亲和力机制研究；将适配体、纳米材料与低场核磁共振技术有机结合，研制EDCs 检测灵敏度高、特异性好的微型智能低场核磁共振生物传感器，建立一套基于高亲和力功能性核酸适体的食品中EDCs低场核磁共振生物传感痕量定量检测新技术。该课题是预防医学、生物学、物理学等多学科交叉的前沿性研究，其研究成果可用于食品安全监控、环境监测、出入境检验检疫等领域，对推动卫生分析化学新技术发展具有很好的理论价值。

食品中环境内分泌干扰物（endocrine disrupting chemicals，EDCs)的危害及滥用越来越得到全世界的重视。其可导致人类精子数量及质量下降、代谢紊乱甚至诱乳腺癌、卵巢癌等。低场核磁共振生物传感检测技术具有快速、受样品基质影响小等优势，有望成为食品中环境内分泌干扰物快速检测的新技术。.本课题以几种典型的EDCs，如双酚A，雌二醇等为靶标，根据靶标的结构特点，通过计算机分子模拟设计、选择相应的核酸序列，制备了相应的高亲和力核酸适配体。以共沉淀法、溶剂热法制备了Fe3O4磁性纳米颗粒，优化了其制备方法、修饰效率来提高探针识别目标物的灵敏度。在此基础上，构建了用于食品体系中双酚A定量分析的弛豫传感器并对弛豫特征信号进行了筛选，LOD为2.9 ng/mL，符合中国设定的安全限度（10 ng/mL）。为提高弛豫传感器的灵敏度，还构建了基于弛豫信号放大的PS-MRS传感器和基于磁选的原理的MS-MRS传感器，其中PS-MRS传感器成功用于测定PC瓶样品中BPA的含量，平均回收率为97.0％~112.7％，RSD均值小于15％，其结果与HPLC相符。在对牛奶样品双酚A的分析中，MS-MRS传感器基于磁选的原理，避免对磁珠浓度及各种交叉反应的优化，提高了灵敏度，在0.5 ng/mL~100 ng/mL浓度范围内与ΔT2W呈线性关系，LOD为0.08 ng/mL。还构建了磁弛豫开关免疫传感器来检测自来水和脱脂牛奶中雌二醇及孕酮残留，LOD为0.01 ng/mL。此外，基于Au@Fe3O4 NPs纳米颗粒和T1-T2二维弛豫信号构建的弛豫传感器可用于鸡蛋中氟苯尼考的快速检测。其RGB分析结果表明，蓝红比值的变化量（△B/R）与目标物浓度存在线性关系，其LOD为5.41 nM。利用二维序列IR-CPMG对0-10 nM浓度范围内的氟苯尼考及氟苯尼考胺可实现同时检测，回收率为93.18-97.98%。最后，还以 Fe3O4超顺磁性纳米颗粒作为基质，通过设计特异性识别目标物的DNA水凝胶层来构建弛豫传感器，实现了自来水与矿泉水中目标物的快速检测且15天内的检测结果保持稳定，LOD为2.682 ng/mL。