Han Ya-Nan, Dong Lei, Sun Lu-Lu, Li Wen-Jia, Xie Jianjing, Li Congyu, Ren Shuhui, Zhang Zhan, Han Hai-Hao, Zhang Zhong
School of Life Science and Technology, Shandong Second Medical University, Weifang 261053, China.
School of Pharmacy, Shandong Second Medical University, Weifang 261053, China.
Molecules. 2025 Mar 8;30(6):1221. doi: 10.3390/molecules30061221.
-galactosidase (-Gal) has emerged as a pivotal biomarker for the comprehensive investigation of diseases associated with cellular senescence. The development of a fluorescent sensor is of considerable importance for precisely detecting the activity and spatial distribution of -Gal. In this study, we developed two excited-state-altering responsive fluorescent sensors ( and ) for ratiometric detection of -Gal. Two TCF dyes, composed of tricyanofuran (TCF) and naphthol units, feature electron "pull-push" systems and are quenched fluorescence by -Gal. Upon -Gal hydrolysis, a significant ratiometric shift in absorption from ca. 475 nm to 630 nm is observed, accompanied by the emergence of a fluorescence signal at ca. 660 nm. The enzyme-responsive optical red-shifts are attributed to the excited-state transition from intramolecular charge transfer (ICT) state to local excited (LE) state, which was confirmed by density functional theory (DFT) calculations. Both fluorescent sensors display exceptional sensitivity and selectivity for the response of -Gal in PBS solution and are capable of tracking -Gal within senescent A549 cells. This study introduces a framework for developing multimodal optical probes by systematically modulating excited-state properties, demonstrating their utility in senescence studies, diagnostic assay design, and therapeutic assessment.
β-半乳糖苷酶（β-Gal）已成为全面研究与细胞衰老相关疾病的关键生物标志物。开发一种荧光传感器对于精确检测β-Gal的活性和空间分布具有相当重要的意义。在本研究中，我们开发了两种用于比率检测β-Gal的激发态改变响应型荧光传感器（和）。由三氰基呋喃（TCF）和萘酚单元组成的两种TCF染料具有电子“推-拉”系统，并被β-Gal淬灭荧光。在β-Gal水解后，观察到吸收光谱从约475 nm到630 nm有明显的比率变化，同时在约660 nm处出现荧光信号。酶响应的光学红移归因于从分子内电荷转移（ICT）态到局域激发（LE）态的激发态跃迁，这通过密度泛函理论（DFT）计算得到证实。两种荧光传感器在PBS溶液中对β-Gal的响应均表现出卓越的灵敏度和选择性，并且能够追踪衰老A549细胞内的β-Gal。本研究通过系统调节激发态性质引入了一个开发多模态光学探针的框架，展示了它们在衰老研究、诊断分析设计和治疗评估中的实用性。
