The discrimination of living and dead cells shows great importance in the development of biology, pathology, medicine, and pharmacology research. Herein, we synthesized a simple benzothiazole-based probe, EP, which was characterized via1H NMR (hydrogen nuclear magnetic resonance) spectroscopy, 13C NMR (carbon nuclear magnetic resonance) spectroscopy and HRMS (high-resolution mass spectroscopy). The fluorescence changes in response to esterase were characterized via fluorescence spectroscopy. EP exhibited a 70-fold fluorescence enhancement in the presence of esterase and possessed a very low limit of detection (4.73 × 10-5 U mL-1). EP also showed high selectivity to esterase compared to other biological species. Bright fluorescence appeared in living cells, which was activated by esterase when incubated with EP. In paraformaldehyde or H2O2 pretreated cells, the fluorescence became very weak since esterase became inactive in these cells. In summary, the EP probe can monitor esterase activity both in vitro and in living cells and can be used to evaluate the health status of cells and discriminate living and dead cells effectively.

中文翻译：

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一种灵敏，快速的“开-关”荧光探针，用于检测酯酶及其在评估细胞状态以及区分活细胞和死细胞中的应用。

活细胞和死细胞的区分在生物学，病理学，医学和药理学研究的发展中显示出重要的意义。在这里，我们合成了一个简单的基于苯并噻唑的探针EP，该探针通过1H NMR（氢核磁共振）光谱，13C NMR（碳核磁共振）光谱和HRMS（高分辨率质谱）表征。响应于酯酶的荧光变化通过荧光光谱表征。EP在存在酯酶的情况下显示出70倍的荧光增强，并且检测限非常低（4.73×10-5 U mL-1）。与其他生物物种相比，EP还显示出对酯酶的高选择性。活细胞中出现明亮的荧光，当与EP孵育时被酯酶激活。在多聚甲醛或H2O2预处理的细胞中，由于酯酶在这些细胞中变得无活性，荧光变得非常弱。总之，EP探针可以监测体外和活细胞中的酯酶活性，并且可以用于评估细胞的健康状况并有效区分活细胞和死细胞。