基于功能化Fe3O4@C核壳型纳米材料调控信号转换的真菌毒素均相电学微阵列适体传感技术研究

Mycotoxin is one of the major nature contaminants, which can pose a threat to the health of humans and animals. This threat is caused either by the direct contamination of agricultural commodities or by a "carry-over" of mycotoxins and their metabolites into animal tissues after feeding of contamied hay. As a consequence of their diverse chemical structures and varying physical properties, mycotoxins can cause acute health disorders, mycotoxicoses. Hence, it is highly important to develop a novel technique for the determination of mycotoxins with high rapid and high accuracy. However, the current detection methods for mycotoxins still exhibit low sensitivity, high false positive, serious samples disruptors and high cost. So, in this project, in order to solve above-mentioned problems, aptamer, single-strand DNA screened by SELEX, is used as recognition molecule with high specificity for mycotoxins. In this project, functionalized Fe3O4@C core-shell nanomaterials are utilized for mediating electrical signal transduction. Special recognition element aptamers, coupled with sensitive microgapped-interdigitated-electrode-arrays-based electrical biosensors, make this project very promising in the development of high-sensitivity, high specificity and high throughput electrical biosensors for mycotoxins. These strategies will make contribution to develop a novel homogenous phase electrical aptasensor technique with the high sensitive, ease operation, low cost, and high throughput for the detection of mycotoxins.

真菌毒素是当前食品安全最为关注的一类污染物，能通过被污染的粮食或饲料以及该饲料喂养的动物等进入人们的食物链，从而对人体表现出致癌性、遗传毒性、致畸性，因此发展快速、准确的真菌毒素检测技术是十分有必要的。本项目针对当前真菌毒素快速检测中存在灵敏度低、假阳性高、基质干扰严重、成本高等问题，将能高特异识别真菌毒素的新型识别分子核酸适体和高灵敏的微阵列电极电学生物传感技术结合起来，拟探索生物功能化Fe3O4@C核壳型磁性纳米材料调控微阵列电极电学信号转换，以实现对真菌毒素的高通量、快速、灵敏筛查，为发展高灵敏度、易操作、低成本、高通量的新型均相电学真菌毒素适体传感技术提供基础。

本项目利用核酸适体修饰的Fe3O4@C、Fe3O4@Au核壳型纳米材料调控微阵列电极电学信号转换初步实现了对真菌毒素的灵敏、特异检测；还利用二维材料黑磷、石墨烯、二硫化钨以及以双链DNA为模板制备了CuNPs荧光指示剂分别介导电化学、荧光信号转换实现了对激酶和真菌毒素的灵敏测定。此外，鉴于碳纳米材料良好的导电性和催化性能，本项目拓展了该类材料在催化氢析出、氧析出、氧还原和锂硫电池中的应用研究。主要工作如下:（1）利用核酸适体修饰的Fe3O4@C、Fe3O4@Au作为导电桥梁调控微阵列电极信号转换，实现了对真菌毒素赭曲霉毒素OTA的灵敏特异检测，由于这两种核壳型材料具有良好的导电性和磁分离聚集功能，避免了当前微阵列电学传感器中需要在电极界面上修饰捕获分子才能介导信号转换的问题，使其在真菌毒素高通量检测方面具有广阔的应用前景。（2）鉴于黑磷良好的导电性和对Cu2+优异的吸附能力以及石墨烯对单链DNA（ssDNA）的特异作用能力，本课题组还分别发展了两种均相电化学传感技术用于激酶灵敏测定，由于不需要在电极界面上对生物分子进行共价修饰，所有的识别反应都在均相溶液中，操作简便，使其在靶标物检测方面具有潜在的应用前景。（3）将二硫化钨和DNA为模板制备的银簇荧光指示剂结合起来，实现了对食品中多种毒素的同时免标记测定；将dsDNA为模板制备了CuNPs荧光指示剂实现了对人血清中甲基化酶的灵敏测定，相关内容发表在Analyst，这两种方法无需标记，操作简便。（4）开发出了一系列功能化的石墨烯和碳纳米管复合材料, 主要包括碳纳米管/石墨烯-S-Al3Ni2、石墨烯/TiO2超轻插层膜、石墨烯/DTT 复合材料、亚纳米硫化钼/碳纳米管、碳纳米管/磷化钴、三维连续空心结构石墨烯网络，以及利用牺牲对电极法制备MoSx-O-PtOx等，这些材料都已被证明在锂硫电池、电解水析氢、析氧以及电催化氧还原中都展现了较好的应用前景，相应的结果已发表在Advanced Materials，ACS Nano，Advanced Science，Journal of Materials Chemistry A，ACS Applied Materials Interfaces，Nanoscale等杂志上。经过课题组四年的努力，相关研究已发表SCI论文共11篇，其中IF>5的论文有9篇。