The estrogen receptors (ERα and ERβ) are vital transcription factors that play important role in physiological functions and are responsible for many hormone-regulated diseases. Herein, we report an environment-sensitive fluorescent probe 2 with a turn-on switch for in situ visualization of the estrogen receptor in living cells. Probe 2 exhibited high ER binding affinity and showed intense fluorescence emission upon binding to ER protein in vitro, and the fluorescence signal was reduced in the presence of a competitive ligand or after ER degradation. With this highly sensitive and selective probe, ER protein degradation was imaged at subcellular level. We believe that this new design strategy might be useful for the development of highly specific fluorescent probes on studies of the function of ER in live cells and related drug discovery.

雌激素受体（ERα和ERβ）是重要的转录因子，在生理功能中起重要作用，并负责许多激素调节性疾病。在本文中，我们报告了一种环境敏感型荧光探针2，该探针带有一个用于在活细胞中原位显示雌激素受体的开启开关。探针2表现出高ER结合亲和力，并在体外与ER蛋白结合后表现出强烈的荧光发射，并且在竞争性配体存在或ER降解后荧光信号降低。使用这种高度敏感和选择性的探针，可以在亚细胞水平上对ER蛋白降解进行成像。我们相信，这种新的设计策略可能对研究ER在活细胞中的功能和相关药物发现方面开发高度特异性的荧光探针很有用。