基于上转换纳米粒子表面印迹的典型全氟化合物分析新方法研究

The project aimed to develop a new method for determination of typical perfluorinated persistent organic pollutants which existed widely in environment, basing on the preparation of a surface imprinted -upconversion nanoparticles. .The preparation method of the new fluorimetric molecular imprinting polymer consisted of three steps: first, upconversion nanoparticles with uniform size and high luminous efficiency were synthesized by hydrothermal related method. Then, the surface imprinted upconversion nanoparticles were synthesized by hydrothermal method which using surfactant modified-nanoparticles as a support, perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA) as template molecule, unsaturated amide with electron-withdrawing group and polyfluorinated alkyl as functional monomer. During the process, the polymer was formed by a carbonized glucose (or tartaric acid, citric acid, etc.) coating on the surface of the luminous particles. Finally, the surface imprinted upconversion nanoparticle composite was obtained after removing the template molecule..In order to obtain high-performance surface imprinted upconversion nanoparticles, the effect of different parameters such as functional monomer, carbon precursor, and polymerization conditions which effect on the morphology, particle size, adsorption capacity as well as fluorescent characteristics of the carbonized substance coated upconversion material were investigated. The composite particles were used as fluorescent probe for detection of PFOS or PFOA in water, and the analytical parameters were obtained. The developed method is simple, sensitive and using high biocompatible material, which will provide a new approach for analysis of trace PFOS and PFOA in environment especially in biological samples.

针对环境中典型全氟化合物检测方法繁琐和不易推广等问题，本项目探索一种基于上转换纳米粒子的表面印迹纳米复合材料的分析新方法。材料的制备包括三个步骤：通过水热法制备粒径均匀、发光效率高的上转换纳米粒子；然后，以改性后的上转换纳米粒子为载体，以全氟辛烷磺酸盐或全氟辛酸为模板分子，以含胺基和多氟代烷基的不饱和酰胺等为功能单体，采用水热碳化技术制备碳包覆的核-壳型纳米印迹粒子；最后，将模板分子洗脱，获得表面印迹上转换荧光纳米粒子。为了获得高性能表面印迹发光粒子，重点研究印迹位点形成的方法和条件，研究不同功能单体、碳前驱体和聚合条件对碳包覆上转换材料表面印迹纳米粒子的形貌、尺寸、结合性能及材料发光性能的影响。将复合粒子作为荧光探针，用于PFOS或PFOA的检测，获得分析参数，并探讨荧光分析识别机理。方法简便、灵敏，所用发光粒子低毒，为环境中痕量典型全氟化合物分析尤其是生物原位分析提供新的方法依据。

针对环境中典型全氟化合物检测方法繁琐和不易推广等问题，本项目主要基于氟-氟弱作用和静电作用构建了高灵敏荧光纳米探针，并进一步结合合适的前处理技术，实现了对环境水样和人血清、蛋类样品基质中PFOS的灵敏测定。主要研究内容和结果如下：（1）基于上转换纳米粒子的三种类型荧光探针和基于碳量子点的荧光探针构建、制备、性能研究和检测应用。所构建分子印迹比率荧光探针和碳点选择性增敏探针对PFOS分析灵敏度较高，检测限可低至pM级，比最近报告的大多数荧光探针低102-104倍；且结合SPE等前处理技术，所建立比率荧光法可用于人血清和鸡蛋中PFOS的加标回收法测定；所建立碳点荧光法可成功用于环境水样中PFOS定量测定；（2）针对荧光法检测对样品前处理要求较高等问题，构建了两种类型绿色磁性碳微球，并用于PFOS分离净化研究，并基于此建立了生物样品中PFOS的荧光检测。所构建磁性双核壳结构介孔碳微球可作为磁性固相萃取（MSPE）材料用于蛋类不同组分萃取液中PFOS的高效分离和富集，且净化后样品可成功被上述所建立碳点荧光增敏法检测，测定结果与HLB柱子前处理（或MSPE）-液质联用分析结果一致；（3）为提高探针材料的吸附容量和检测灵敏度，研究还构建了基于镧系金属有机骨架本身和其包覆的上转换纳米粒子荧光探针，基于静电或氟-氟作用实现对PFOS灵敏检测，LOD达到0.1pM。整体上而言，研究中所构建分子印迹型和氟配体型的荧光探针具有对PFOS检测灵敏度高、选择性好和线性范围宽等优势，结合合适的样品前处理技术，可用于地表水样乃至生物基质样品中PFOS定量分析，且这种联用技术也有望推广于更多实际样品的荧光检测应用。此外，所制备双核壳结构磁性介孔碳微球作为磁性固相萃取剂具有处理样品体积大、回收率高、富集分离速度快等特点，对多种复杂样品中全氟化合物的分离净化将具有潜在应用价值。项目执行过程中，在《分析化学》和《Journal of Hazardous Materials》等国内外知名期刊上发表研究论文8篇，申请中国发明专利5项，培养青年学者1名，硕士研究生5名。