Biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) play important roles in various physiological and pathological processes. However, it is still a great challenge to selectively detect Cys/Hcy and GSH in biological samples due to the similarity of structures and re-activities of these biothiols. In this paper, a new dual-channel near infrared-7-nitro-1,2,3-benzoxadiazole (NIR-NBD) fluorescent probe has been developed for the discriminative detection of Cys/Hcy and GSH. The probe is composed of two functional parts: a near-infrared dye of dicyanoisophorone, as fluorophore precursor, and NBD as both fluorophore precursor and sensing group. It was observed that NIR-NBD probe displayed two different fluorescent signals in response to biothiols, green-red for Cys/Hcy and red for GSH. It also showed a near infrared emission (756 nm), low detection limit, fast response, high stability, selectivity and sensitivity. Furthermore, NIR-NBD was effectively applied for the discriminative detection of Cys/Hcy and GSH in HeLa cells.

半胱氨酸（Cys），高半胱氨酸（Hcy）和谷胱甘肽（GSH）等生物硫醇在各种生理和病理过程中均起重要作用。然而，由于这些生物硫醇的结构相似性和反应性相似，因此选择性检测生物样品中的Cys / Hcy和GSH仍然是一个巨大的挑战。本文开发了一种新的双通道近红外7-硝基-1,2,3-苯并恶二唑（NIR-NBD）荧光探针，用于判别检测Cys / Hcy和GSH。该探针由两个功能部分组成：作为荧光团前体的双氰基异佛尔酮的近红外染料，以及作为荧光团前体和传感基团的NBD。据观察，NIR-NBD探针响应生物硫醇显示两种不同的荧光信号，绿红色表示Cys / Hcy，红色表示GSH。它还显示了近红外发射（756 nm），低检测限，快速响应，高稳定性，选择性和灵敏度。此外，NIR-NBD有效地用于HeLa细胞中Cys / Hcy和GSH的判别检测。