Reactive sulfur species (RSS) play pivotal roles in various pathological and physiological processes. There exists an intricate relevance in generation and metabolism among these substances. Although they are nucleophilic, there are still some differences in their reactivity. There are many methods to detect them by using reactive fluorescent probes, but the systematic study of their reactivity is still lacking. In our study, we designed a multiple reaction site fluorescent probe based on benzene conjugated benzopyrylium and NBD. The study revealed that besides both biothiols and hydrogen sulfide, sulfur dioxide (SO₂) can cleave the ether bond. There are two reaction forms for GSH with low reactivity: cutting the ether bond and adding the conjugated double bond of benzopyrylium. Nevertheless, Cys/Hcy with higher activity can further rearrange with NBD after cutting the ether bond. In addition, SO₂ can not only cleave the ether bond, but also continue to add the conjugated double bond of benzopyrylium. The above processes lead to multicolor emission of the probe, thus realizing the characteristic analysis of different sulfides. Thus the probe can be used for the detection of sulfide in mitochondria, and further for the imaging of sulfide in cells and zebrafish. This effective analysis method will provide a broad application prospect for practical applications.

中文翻译：

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硫化物活性依赖性多色发光染料及其在体内成像中的应用

活性硫物质 (RSS) 在各种病理和生理过程中起着关键作用。这些物质的生成和代谢之间存在着错综复杂的关联。虽然它们是亲核的，但它们的反应性仍然存在一些差异。使用反应性荧光探针检测它们的方法很多，但对其反应性的系统研究仍然缺乏。在我们的研究中，我们设计了一种基于苯共轭苯并吡喃和 NBD 的多反应位点荧光探针。研究表明，除了生物硫醇和硫化氢，二氧化硫（SO ₂) 可以裂解醚键。低反应性的GSH有两种反应形式：切断醚键和加入苯并吡喃的共轭双键。然而，具有较高活性的 Cys/Hcy 在切断醚键后可以进一步与 NBD 重排。此外，SO ₂不仅可以裂解醚键，还可以继续添加苯并吡喃的共轭双键。上述过程导致探针发出多色光，从而实现对不同硫化物的特性分析。因此该探针可用于检测线粒体中的硫化物，并进一步用于细胞和斑马鱼中硫化物的成像。这种有效的分析方法将为实际应用提供广阔的应用前景。