基于信号扩增技术构建的超灵敏裸眼分析水体中汞的新方法研究

Mercury, a global pollutant, received extensive attention owing to its high toxicity. It is of great value to establish highly selective and ultrasensitive methods for the determination of mercury species by the naked-eye. In this application, based on the specific reaction of mercury species, employed vinyl ether and thiocarbamate as recognition receptor, the indicators for inorganic and organic mercury species would be designed and synthesized to detect mercury species with excellent selectivity. In view of polymerase chain reaction (PCR) mechanism, combined with circulatory system of generation of hydrogen peroxide (H2O2), adopted molecule with high molar absorption coefficient as the signal function group, new small organic molecules with self-immolative moieties mediated by H2O2 would be equipped to act as signal amplification reagents. The amplified signal would be obtained by the initiation of target analytes, and thus ultrasensitive analysis by the naked-eye would be successfully achieved. New methods for the ultrasensitive determination of mercury species by the naked-eye would be established based on the effective combination of the signal amplification systems and mercury indicators. The structure-activity relationship between the signal amplification reagents and stability, response time, and signal amplification factor would be investigated in detail. The inherent reaction mechanism of ultrasensitive analysis would be disclosed based on the synergistic action of circulatory system of generation of H2O2, the signal amplification reagents and mercury indicators. The obtained results will provide a new strategy to develop highly selective and ultrasensitive methods for the determination of other toxic species by the naked-eye.

汞一直是备受关注的全球性污染物，建立高选择超灵敏裸眼分析汞的方法具有重要的应用价值。本项目借鉴汞的专一性反应，以乙烯基醚、硫代氨基甲酸酯作为识别功能团，设计合成无机汞和有机汞均响应的探针试剂，实现汞的高选择性测定。基于聚合酶链式反应机制，结合循环产生过氧化氢的系统，采用摩尔吸光系数大的有机分子作为信号功能团，构建由过氧化氢调控自衰减过程的新型有机小分子信号扩增平台，可将目标物诱导的信号放大，实现超灵敏的裸眼分析。利用信号扩增体系和汞探针试剂的有效结合，建立裸眼分析汞的新方法，可实现汞的高选择性和超灵敏分析。确定信号扩增平台的结构与稳定性、响应时间以及信号放大倍数之间的构效关系，阐明循环产生过氧化氢体系、信号扩增平台和汞试剂之间的协同效应，揭示高选择超灵敏分析方法的内在机制，为其它有毒物质高选择性、超灵敏裸眼检测系统的建立奠定基础。

重金属汞严重威胁着生态环境和人类健康，一直是备受关注的全球性污染物。水环境中汞的裸眼灵敏检测和活体内汞的原位荧光成像分析具有重要意义。本项目以构建具有裸眼分析、超灵敏、特异性、快速响应、良好水溶性等优异性能的汞离子比色荧光探针，进而建立水环境中汞的超灵敏裸眼分析和活体内汞离子原位荧光成像分析为研究目标，在项目实施过程中，首先设计合成了多种具有摩尔吸光系数大、光稳定性好、吸收/发射波长长等优异性能的比色荧光染料，进一步构建简单比色荧光探针来考察其光谱性能；另一方面，采用灵敏特异性反应型识别受体构建新型汞离子比色荧光探针。利用碱、过氧化氢等物质作为催化信号放大试剂，建立汞的超灵敏分析方法。经过3年的努力研究，现已成功制备了7个超灵敏特异性汞离子比色荧光探针，并成功应用于水环境中汞离子的裸眼分析和活体内汞离子的原位荧光成像分析。本项目的实施不仅为水环境中汞的裸眼灵敏检测和活体内汞的原位荧光成像分析提供了新的手段，而且还为其它有毒物质超灵敏特异性检测系统的建立奠定了基础。到目前为止，在本项目的支持下已发表SCI论文26篇，其中影响因子5.0以上论文14篇，包括Analytical Chemistry, ACS Sensors, Biosensors & Bioelectronics, Sensors and Actuators B: Chemical等；另外，已授权国家发明专利5项；培养硕士研究生6名，已毕业3名，另外3名硕士研究生预计2020年6月毕业。