近红外H2S荧光探针研究进展

硫化氢（H₂S）是一种具有臭鸡蛋气味的无色气体，其不但存在于外界环境中，而且是继一氧化氮（NO）和一氧化碳（CO）之后生物系统中第三种重要的内源性气体信号分子，近年来因其对人类健康和疾病的影响而越来越受关注。H₂S可以作为抗氧化剂清除人体内的活性氧（ROS）和活性氮（RNS），参与多种细胞的生理反应，包括细胞凋亡、血管舒张、神经调节等，是多种组织中的细胞保护剂和气体传递剂。现代医学研究已证实硫化氢含量与糖尿病、阿尔茨海默病、帕金森病等特定疾病密切相关，但人们尚不清楚H₂S影响细胞信号传导和其他生理事件的具体分子机制，因此开发用于可视化内源性H₂S的方法、研究其在细胞和生物体中的动态分布将具有非常重要的意义。目前检测H₂S浓度的近红外（NIR）荧光探针是一个研究的热点，这是因为在生物样本分析时近红外荧光探针具有许多显著的优点：光损伤更小、能穿透更深的组织、背景自荧光干扰低。在分子水平上，H₂S表现出独特的化学特性，既是良好的还原剂，又是良好的亲核试剂，用于H₂S选择性检测的近红外荧光探针设计策略主要包括叠氮化物和硝基的还原、亲核进攻、加成反应等。该文章综述了近三年近红外H₂S荧光探针的设计合成、识别机理、探针的性能及其在细胞或生物体中的荧光成像研究与最新进展，最后，对该类探针的未来研究方向和发展趋势进行了展望。

Research Progress of Near-Infrared Fluorescent Probes for Hydrogen Sulfide

Hydrogen sulfide (H₂S) is a colorless gas with the unpleasant smell of rotten eggs. It not only exists in the environment but was also considered the third important endogenous gaseous transmitter following nitric oxide (NO) and carbon monoxide (CO) in biological systems. H₂S has recently attracted more attention for contributing to human health and disease. H₂S has important biological functions and has been recognized as a cytoprotectant and gasotransmitter in many tissue types, including mediating vascular tone in blood vessels and neuromodulation in the brain. Hydrogen sulfide concentration has been demonstrated to be closely correlated with particular diseases in modern medical research, such as diabetes, Alzheimer’s disease and Parkinson’s disease. The molecular mechanisms by which H₂S affects cell signaling and other physiological events remain unclear. Therefore, it is necessary to develop highly sensitive and selective methods for detecting the concentration of H₂S in living cells and organisms. The near-infrared fluorescent probe for detecting H₂S has been the research hotspot. Near-infrared (NIR) fluorescent probes have several significant advantages for imaging applications in vivo: negligible photodamage, deep tissue penetration, and low interference from background auto fluorescence. Many new methods for visualizing H₂S in living systems have been reported. At the molecular level, H₂S exhibits unique chemical characteristics, acting as a good reducing agent and a good nucleophile. Thus the main strategies used in NIR fluorescent probe development for H₂S detection include azide and nitro group reduction, nucleophilic attack, addition reaction, etc. Herein, the design and synthesis, recognition mechanism, properties of NIR fluorescent probes for H₂S and their fluorescence imaging in cells and organisms and the latest research progress reported in recent three years have been reviewed. Finally, in our opinion, the future research direction and development trend of this kind of probes are prospect.