基于共轭集聚作用的羟基多环芳烃原位富集传感研究

Polycyclic aromatic hydrocarbons (PAHs) are compounds widespread in the environment and food, many of them showing carcinogenic effects. Human urinary hydroxylated metabolites (OH-PAHs) are a class of PAH metabolites used as biomarkers for estimating human internal exposure to PAHs. However, using only one or several biomarkers cannot reflect internal exposure level of PAHs. The present project will systematically examine the electrochemical behaviors of typical OH-PAHs such as homologous compounds, isomers by benzene ring, K region and L region hydroxylated OH-PAHs. Statistical analysis is performed based on the above results to verify our proposals, “1) Increasing the number of confused benzene on the light OH-PAHs significantly affect the electrochemical redox properties; 2) The influence on the redox peaks is negligible for heavy OH-PAHs; 3) The effects decrease with the increase of the benzene ring”. Graphene, a two-dimensional atomically thick crystal containing highly delocalized π electrons, is an excellent candidate for preconcentration of OH-PAHs. However, the two-dimensional nature of graphene brings another great challenge: it tends to re-aggregate due to π-π interactions between graphene layers. Thus, conductive conjugated poly(3-alkyl-thiophene)s are electropolymerized with graphene in this project. The composite films will be used to pre-concentrate OH-PAHs via π-π-π compacting interaction. The adsorption isotherms such as using Freundlich and Bruauer, Emmet & Teller (BET) models will be used to fit the pure component experimental data. Combined with the achieved preconcentration, in situ electrochemical sensing will be employed to determinate total OH-PAHs. If successful, the proposed research will provide an in-depth understanding of how these OH-PAHs oxidized at solid electrodes and enable a new methodology for characterizing and classifying of OH-PAHs. The results of this project also provides reference of electrochemical properties of OH-PAHs and develop an inexpensive, sensitive, and reliable method for evaluating the internal exposure level of PAHs.

多环芳烃(PAHs)是发现最早且数量最多的致癌物，其代谢产物羟基多环芳烃(OH-PAHs）作为生物标志物综合评价人体对PAHs内暴露情况已被广泛接受。然而不论选择哪个或者哪几个OH-PAHs都不能真实反映PAHs的内暴露水平。本项目在充分研究OH-PAHs同系结构、环位异构和羟基取代区域异构(K区和L区)电化学氧化还原特性的基础上，验证我们提出的“轻质PAHs代谢物苯环数量的增加对其电化学氧化还原性质影响显著；重质苯环的数量影响变小；苯环数量越多，影响越小”的假设。采用具有线性离域π电子体系的聚烷基噻吩导电聚合物共轭贯穿二维石墨烯，通过共轭集聚作用选择性富集零维OH-PAHs，采用Freundlich和BET方程进行拟合，计算热力学函数，推测吸附机理；总结氧化电位规律，按照相似统一、相差分类的原则，实现OH-PAHs总量测定，为PAHs人体暴露水平评价提供一种简单、高效且灵敏的分析新方法。

多环芳烃(PAHs)是发现最早且数量最多的致癌物，其代谢产物羟基多环芳烃(OH-PAHs）作为生物标志物综合评价人体对PAHs内暴露情况已被广泛接受。然而当前我国对PAHs的研究主要集中在环境和各种食品中PAHs的含量测定，而对人体PAHs暴露水平评价却很少。本项目设计并制备还原氧化石墨烯（E-rGO）、聚蒽喹啉导电聚合物/石墨烯复合膜{GR-AQ}n、苯/咔唑水溶性导电聚合物/石墨烯复合膜{GR-PPC}n、共价有机骨架材料COF-CTpPa-2等多种富π体系纳米传感修饰电极。利用扫描电镜、X射线衍射仪、红外光谱、拉曼光谱、紫外吸收光谱、荧光光谱、循环伏安法和电化学阻抗等对该修饰电极的组装、形貌、结构、晶型、导电性等进行表征。选取了1-羟基芘、3-羟基菲、α-萘酚、β-萘酚等OH-PAHs作为研究对象，利用计算机软件模拟其分子尺寸，通过循环伏安、电化学阻抗、差分脉冲伏安等手段研究OH-PAHs的电化学氧化还原性质，探讨相互作用机制，从孔径匹配、共轭结构及键合作用等方面探究OH-PAHs的电化学行为规律，考察苯环数量、羟基位置对 OH-PAHs 电化学氧化还原性质和传感性质的影响。在获得OH-PAHs 电化学性质的基础上，总结规律，将1-羟基芘、3-羟基菲、α-萘酚、β-萘酚这些有代表性的OH-PAHs的标准溶液相互混合，构建模型，优化电解质溶液pH，富集电位、富集时间，扫描速度，自组装层数等，考察OH-PAHs体系π电子通过π-π共轭作用、电位富集协同原位富集电化学传感效果，建立集原位富集和电化学传感一体化的测定方法，并应用于人体尿液中OH-PAHs的的测定，为PAHs人体暴露水平评价提供一种简单、高效且灵敏的分析新方法。