Neutrophil elastase (NE) is an important regulator of immune response and is widely regarded as a biomarker for inflammatory diseases. To date, all the NE probe is designed by linking pentafluoropropionyl and amino-containing fluorophores through amide bond. This method is limited by the fluorophores, which must contain amino functional groups. To overcome this problem, we use the self-immolative group to convert hydroxyl groups to fluorophores HFC (4-trifluoromethyl-7-hydroxyl coumarin) into amino groups, and to connect recognition groups (pentafluoropropionyl) to construct a novel NE fluorescent probe HFC-NE. Predictably, HFC-NE can detect NE activity selectively and sensitively with many advantages, such as good water solubility and biocompatibility, high fluorescence enhancement and high affinity. Besides, HFC-NE is successfully applied to real-time and specific detection of NE activity in living cells and zebrafish models. These excellent outcomes confirmed that this strategy based on self-immolative group is a useful method to design more NE fluorescent probes.

中性粒细胞弹性蛋白酶 (NE) 是免疫反应的重要调节因子，被广泛认为是炎症性疾病的生物标志物。迄今为止，所有的NE探针都是通过酰胺键连接五氟丙酰基和含氨基的荧光团而设计的。这种方法受到荧光团的限制，荧光团必须含有氨基官能团。为了克服这个问题，我们利用自焚基团将荧光团HFC（4-三氟甲基-7-羟基香豆素）的羟基转化为氨基，并连接识别基团（五氟丙酰基），构建了一种新型NE荧光探针HFC-东北_ 可以预见，HFC-NE具有良好的水溶性和生物相容性、高荧光增强和高亲和力等优点，可以选择性、灵敏地检测NE活性。此外，HFC-NE成功应用于活细胞和斑马鱼模型中 NE 活性的实时和特异性检测。这些优异的结果证实了这种基于自焚组的策略是设计更多NE荧光探针的有效方法。