Biothiols such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) play vital roles in various physiological and pathological processes. In this work, a BODIPY-based fluorescent probe XCN was synthesized from multi-step reactions. We first synthesized a BODIPY derivative with a cyano and a bromine moiety attached to the 8-diphenylaminophenyl substituent of BODIPY, followed by the reaction with p-aminothiophenol under basic condition. Interestingly, compound XCN was successfully obtained with the p-aminophenylthio moiety introduced into one of the α-positions of the pyrrolic units. This reaction may compose an efficient approach for synthesizing novel BODIPY derivatives with substituents attached to the pyrrolic unit without previously brominating it. XCN can be used as a fluorescence turn-on probe to selectively detect Cys and Hcy using the cyano group as the recognition site, with the p-aminophenylthio moiety left unreacted. XCN was found to be nearly nonfluorescent, and it exhibits only slight fluorescence enhancement when treated with GSH. However, upon interaction with Cys or Hcy, the fluorescence was enhanced by 1081 and 1126 folds, respectively. In addition, XCN exhibits good selectivity and sensitivity towards Cys and Hcy over GSH and other amino acids in a wide pH range from 2 to 10 in aqueous buffers. Furthermore, XCN was successfully used for imaging biothiols in living A549 lung cancer 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起着至关重要的作用。在这项工作中，由多步反应合成了基于BODIPY的荧光探针XCN。我们首先合成了一个带有氰基和一个与BODIPY的8-二苯基氨基苯基取代基相连的溴部分​​的BODIPY衍生物，然后在碱性条件下与对氨基硫酚反应。有趣的是，化合物XCN成功与所获得的p引入到吡咯单元的α-位之一的-氨基苯硫基部分。该反应可以构成合成具有新颖的BODIPY衍生物的有效方法，该衍生物具有与吡咯单元相连的取代基，而无需事先溴化。XCN可用作荧光开启探针，使用氰基作为识别位点选择性检测Cys和Hcy，而对氨基苯硫基部分未反应。发现XCN几乎是无荧光的，用GSH处理时，XCN仅表现出轻微的荧光增强。但是，与Cys或Hcy相互作用后，荧光强度分别提高了1081倍和1126倍。另外，XCN在水性缓冲液中，在2至10的宽pH范围内，对GSH和其他氨基酸显示出对Cys和Hcy良好的选择性和敏感性。此外，XCN已成功用于活A549肺癌细胞中生物硫醇的成像。