近红外化学发光汞探针的制备及其在汞形态成像分析中的应用

The toxicity of mercury is closely related to its inherent speciation. The in situ imaging method of mercury speciation is an effective technique to reveal the distribution of mercury and the mechanism of toxicity in living organisms. Chemiluminescent probe for in vivo bioimaging possesses higher sensitivity because it does not need external light excitation, but the existing stumbling blocks including low chemiluminescence efficiency, short emission wavelength and lifetime seriously limit its application. Based on the mechanism of chemiluminescence resonance energy transfer (CRET), new chemiluminescence-near infrared fluorophore conjugates with high brightness, long emission wavelength and lifetime would be constructed. Subsequently, taking full advantage of the chemiluminescence and energy transfer process mediated by the reaction-based recognition receptors, new near infrared chemiluminescent probes with different response rate of inorganic mercury and organic mercury were designed and synthesized. The distinction of mercury speciation would be achieved based on their different response speed. Thus, new methods for in vivo imaging of inorganic and organic mercury would be successfully obtained. Taking the mice and zebrafish as in vivo model, the concentration and distribution of mercury speciation in the different organs would be determined by the proposed methods. The implementation of the project will develop new techniques for speciation analysis of mercury, and provide an effective technical means for the further study of the distribution and transformation of mercury speciation and the molecular mechanism of mercury toxicity.

汞的毒性与其具体形态密切相关，汞形态的原位成像方法是揭示生物活体内汞的分布和毒性机制的有效手段。基于化学发光探针的成像分析因不需要光激发而具有更高的灵敏度，但现有的化学发光探针存在发光效率较低以及发射波长和发光寿命短等不足，严重制约了其在活体成像分析中的应用。本项目拟基于化学发光能量转移机制，构建化学发光-近红外荧光团杂化的新型高亮度、长发射波长和寿命的化学发光体系。采用反应型识别受体调控化学发光和能量转移过程的策略，设计合成对无机汞和有机汞具有不同响应速率的近红外化学发光探针；利用其不同的响应速度来实现汞形态的区分识别，发展生物活体内无机汞和有机汞的成像分析新方法；选取小鼠和斑马鱼作为活体模型，对其体内不同器官中汞形态浓度水平和分布进行超灵敏成像分析。项目的实施，将发展汞形态成像分析新技术，为深入研究生物体内汞形态的分布和转化以及汞毒性的分子机制提供有效的技术手段。

重金属汞具有持久性、高度生物蓄积性和剧毒性，一直是备受关注的全球性污染物。开发活体内汞物种的原位灵敏检测技术是进一步揭示其在生物体内具体分子机制和毒理的关键。. 鉴于此，为了获得用于汞物种原位超灵敏检测技术，基于不同的识别传感机制，采用新型荧光染料和识别受体，成功构建了一系列特异性超灵敏汞比色荧光探针，并成功运用于水环境汞的灵敏分析和生物体系内汞的原位成像检测。首先基于试卤灵、双氰基异氟尔酮、7-羟基香豆素、三氰基呋喃、半萘酚罗丹荧、尼罗蓝、7-二乙氨基香豆素等染料母体成功开发了一系列新型高亮度荧光染料；鉴于汞物种与环状酰亚胺的特殊配位形式和对硫原子的强亲和特性，筛选/创制了环状酰亚胺类、二甲氨基硫代甲酸酯、硫代碳酸苯酯、1,4-二硫苏糖醇、丙硫醇、2-巯基乙醇等一系列汞物种识别受体；在此基础上，以研制的新型荧光染料作为信号功能团，成功开发了一系列水溶性、低毒性、特异性超灵敏汞比色荧光探针，并系统研究了其识别特性，并将性能优异的荧光探针应用于活细胞和斑马鱼体内汞的超灵敏原位成像分析。该研究不仅为深入研究人体内汞的具体分子机制和毒理提供了急需的数据支持，而且为用于生物体内其他物种超灵敏成像的比色荧光探针的设计积累了经验，并提供了一系列性能优异的荧光染料。. 四年来，在本项目的支持下，在Coordination Chemistry Reviews、Analytical Chemistry、Chemical Communications、Biosensors and Bioelectronics、ACS Sensors、Sensors and Actuators B: Chemical、Journal of Agricultural and Food Chemistry、Analyst、Chinese Chemical Letters等期刊上发表SCI论文56篇，其中影响因子3.0以上论文50篇，中科院一区论文21篇；授权国家发明专利13项；获得山东省高等学校优秀科研成果三等奖1项。培养硕士研究生9人，已毕业7人，拟于2022年6月毕业2人；另外，其他在读博士研究生1人，硕士研究生7人。