Small molecule biothiols, such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), are important biomarkers and play vital roles in many physiological processes. Due to their similarity in structure and function, it is still a challenge to develop probes that can simultaneously distinguish Cys, Hcy and GSH from each other. Lysosome is a major subcellular organelle in living cells that contains approximately 50 different degradative enzymes, and biothiols play an important role in lysosome. Herein, we developed a lysosome-targetable probe Lyso-O-NBD for simultaneous detection and discrimination of Cys/Hcy and GSH by dual channels. Under double-wavelength excitation of 400 nm and 470 nm, the probe Lyso-O-NBD showed high selectivity and sensitivity towards Cys/Hcy and GSH over other amino acids and ions. Furthermore, the probe Lyso-O-NBD could be used for simultaneous detection and discrimination of Cys/Hcy and GSH in lysosome of living cells with low cytotoxicity.

小分子生物硫醇，例如半胱氨酸（Cys），高半胱氨酸（Hcy）和谷胱甘肽（GSH），是重要的生物标志物，在许多生理过程中起着至关重要的作用。由于它们在结构和功能上的相似性，开发能够同时区分Cys，Hcy和GSH的探针仍然是一个挑战。溶酶体是活细胞中的主要亚细胞器，包含大约50种不同的降解酶，而生物硫醇在溶酶体中起重要作用。本文中，我们开发了一种可靶向溶酶体的探针Lyso-O-NBD，用于通过双通道同时检测和区分Cys / Hcy和GSH。Lyso-O-NBD探针在400 nm和470 nm的双波长激发下对其他氨基酸和离子显示出对Cys / Hcy和GSH的高选择性和敏感性。此外，探针Lyso-O-NBD可用于同时检测和鉴别低细胞毒性活细胞溶酶体中的Cys / Hcy和GSH。