基于大环主体分子修饰多功能纳米酶的食品危害物识别与检测方法研究

The surface modification of nanozymes has great potentiality of developing nanosensors for food hazards. However, the development of nanozyme- based sensors for food hazards was vastly constrained by the limited interaction between food hazards and nanozymes. In order to break through this bottleneck, some macrocyclic host modified magnetic nanohybrid-based or nanocomposite-based nanozymes will be prepared in this proposal. The recognition and enrichment of the macrocyclic hosts modified nanozymes for typical food hazards such as anabolic steroids will be investigated. Meanwhile, the roles of some key factors, including macrocyclic host modification, host-gust recognition and the selection of catlytic substrates, will be revealed in regulating the activity of the above macrocyclic host modified magnetic nanozymes. In addition, a new platform of rapid screening detection and differential sensing methods for the typical food hazards, anabolic steroids, will be established. The above research will not only develop a new category of highly sensitive, selective, easy-to-use, and low-cost detection methods for food hazards, but also provide a novel strategy for the development of nanozyme-based sensors.

纳米酶的表面修饰是极具潜力的食品危害物传感检测方法构建途径；但是，由于食品危害物与纳米酶的作用方式有限，这极大地约束了食品危害物纳米酶传感方法的发展。针对这一瓶颈，本项目拟通过制备多种大环主体分子修饰的杂合/复合型磁性纳米酶，研究该类纳米酶对甾类同化激素等典型食品危害物的识别和富集功能，明确大环主体分子修饰、客体分子识别、催化底物选择等关键因素对纳米酶活性调节的规律；同时，针对食品中残留甾类同化激素等典型危害物，构建基于纳米酶的快速筛选检测和区分检测新平台。本项目的研究将构建一类高灵敏、高选择性、操作便捷、成本较低的食品危害物检测新方法，并为纳米酶传感技术的发展提供新思路。

针对纳米酶应用于食品危害物检测通常依赖酶的现状，项目基于农药等对纳米模拟酶表面活性的直接调控，发展了多种新型的高灵敏纳米酶比色检测方法。代表性案例包括：①制备了三维多孔铈掺杂GO纳米带(Ce-GONRs)纳米酶，发现丁醚脲和西维因选择性抑制其活性，实现了高灵敏无酶农药比色检测；②制备了β-CD增强活性β-CD@DNA-CuNCs纳米酶，发现草甘膦络合可破坏β-CD@DNA-CuNC表面Cu2+/Cu+物种的协同作用，实现了高灵敏度无酶草甘膦比色检测；③发现S2O32-可加速Pb2+刻蚀Au@PtNCs表面，降低其催化活性，实现了高灵敏的Pb2+比色检测；④发现3种有机磷农药可通过金属-S键吸附到超薄壳层的Au@Pt NPs表面,遮蔽其表面的活性位点，促使其团聚,实现了高灵敏的有机磷农药比色检测；⑤制备了纳米铈交联GO纳米带(Ce-GONRs)和异原子掺杂的GONRs(Ce-BGONRs和Ce-NGONRs)，可作为高活性复合纳米酶，发现西维因、丁醚脲等6种杀虫剂可与纳米酶产生指纹反应，构建了三元件比色传感器阵列。应用LDA和HCA分析，传感阵列实现了0.1 ~ 50 μg/mL范围内6种农药和不同比例的2种农药混合物实现检测和鉴别。上述研究采用主体大环分子修饰、金属纳米/石墨烯复合等方法显著提升了纳米酶的活性；利用目标分子与纳米酶的络合、氢键、π-π堆积等多种作用协同，强化其与纳米酶的作用，从而提高食品危害物比色检测方法的灵敏度和选择性。上述研究为基于纳米酶的小分子传感方法提供了更简洁更经济的开发策略。.项目还提出一种小分子适配体-侧流层析分析（Apt-LFA）新模式并开发了多项Apt-LFA等方法；并通过主客体识别、AIE等作用开发了多种食品危害物高灵敏荧光纳米簇传感方法。上述研究为利用荧光纳米簇和Apt-LFA理性设计食品危害物传感方法提供了重要的研究策略。