We present a lysosome-targetable and ratiometric fluorescent probe, TJ2, for visually monitoring exogenous and endogenous HOCl in living cells by using a built-in S atom within the π-extended rhodamine fluorophore as a pH-independent recognition site. Based on the oxidation-promoted intramolecular charge transfer processes, TJ2 demonstrates fast ratiometric fluorescence response, excellent selectivity, and high sensitivity (2.3 nM) toward HOCl. Furthermore, TJ2 is highly lysosome-targetable, which could be used for ratiometric monitoring of the levels of HOCl in lysosomes.

中文翻译：

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次氯酸比例荧光探针及其生物学应用

我们提出了一种溶酶体靶向和比例荧光探针TJ2，用于通过使用π延伸的若丹明荧光团内的内置S原子作为pH无关的识别位点，目视监测活细胞中的外源性和内源性HOCl。基于氧化促进的分子内电荷转移过程，TJ2表现出快速的配比荧光响应，出色的选择性和对HOCl的高灵敏度（2.3 nM）。此外，TJ2具有高度的溶酶体靶向性，可用于比率监测溶酶体中HOCl的水平。