The ability to detect and visualize cellular events and associated biological analytes is essential for the understanding of their physiological and pathological functions. Cysteine (Cys) plays a crucial role in biological systems and lysosomal homeostasis. This puts forward higher requirements on the performance of the probe. Herein, we rationally designed a coumarin-based probe for the reversible, specific, sensitive, and rapid detection of Cys based on pH regulating reactivity. The obtained probe (ECMA) introduces a morpholine moiety to target lysosomes, and α,β-unsaturated-ketone with an electron-withdrawing CN group served as a reversible reaction site for Cys. Importantly, ECMA was successfully applied to the real-time monitoring of Cys dynamics in living cells. Furthermore, cell imaging clearly revealed that exogenous Cys could induce the up-regulation of lysosomal ROS, which provided a powerful tool for investigating the relationship between oxidative stress and lysosomal Cys.

中文翻译：

---

基于溶酶体靶向荧光探针的 pH 调节反应性，用于跟踪氧化应激下的半胱氨酸动态

检测和可视化细胞事件和相关生物分析物的能力对于理解它们的生理和病理功能至关重要。半胱氨酸（Cys）在生物系统和溶酶体稳态中发挥着至关重要的作用。这对探头的性能提出了更高的要求。在此，我们合理设计了一种基于香豆素的探针，用于基于pH调节反应性的可逆、特异、灵敏、快速检测Cys。所获得的探针（ECMA）将吗啉部分引入到溶酶体中，并且带有吸电子CN基团的α,β-不饱和酮作为Cys的可逆反应位点。重要的是，ECMA 已成功应用于活细胞中 Cys 动态的实时监测。此外，细胞成像清楚地揭示了外源性Cys可以诱导溶酶体ROS的上调，这为研究氧化应激与溶酶体Cys之间的关系提供了有力的工具。