In this work, A new near-infrared (NIR) fluorescent probe NIR-L based on dicyanoisophorone was rationally designed, synthesized and characterized for the detection of cysteine (Cys). This probe exhibited highly selective and sensitive response to Cys over other analytes including amino acids, cations and anions under physiological conditions, which can be identified by naked eyes. It was found that the probe showed NIR fluorescence turn-on response at 714 nm toward Cys with a large Stokes shift of 174 nm and a very low detection limit of 28.6 nM. The results of ¹H NMR and DFT calculation further confirmed that the addition of Cys triggered a reaction between Cys and NIR-L, leading to the release of a NIR fluorescent dye NIR-OH. Moreover, NIR-L was successfully used to realize the in vivo Cys bioimaging in HeLa cells and mice. Significantly, the sensing system was applied in imaging of Cys in B16-F10 tumor-bearing mice.

本工作合理设计、合成并表征了一种基于二氰基异佛尔酮的新型近红外（NIR）荧光探针NIR-L ，用于检测半胱氨酸（Cys）。该探针在生理条件下对Cys的选择性和灵敏度高于其他分析物，包括氨基酸、阳离子和阴离子，肉眼可识别。发现该探针在 714 nm 处对 Cys 显示出 NIR 荧光开启响应，具有 174 nm 的大斯托克斯位移和 28.6 nM 的极低检测限。¹ H NMR和DFT计算的结果进一步证实了Cys的加入引发了Cys和NIR-L之间的反应，导致释放出NIR荧光染料NIR-OH. 此外，NIR-L已成功用于实现 HeLa 细胞和小鼠体内 Cys 生物成像。值得注意的是，该传感系统应用于 B16-F10 荷瘤小鼠的 Cys 成像。