School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China.
Angew Chem Int Ed Engl. 2023 Nov 6;62(45):e202307641. doi: 10.1002/anie.202307641. Epub 2023 Jul 31.
The advancement of fluorescence microscopy techniques has opened up new opportunities for visualizing proteins and unraveling their functions in living biological systems. Small-molecule organic dyes, which possess exceptional photophysical properties, small size, and high photostability, serve as powerful fluorescent reporters in protein imaging. However, achieving high-contrast live-cell labeling of target proteins with conventional organic dyes remains a considerable challenge in bioimaging and biosensing due to their inadequate cell permeability and high background signal. Over the past decade, a novel generation of fluorogenic and cell-permeable dyes has been developed, which have substantially improved live-cell protein labeling by fine-tuning the reversible equilibrium between a cell-permeable, nonfluorescent spirocyclic state (unbound) and a fluorescent zwitterion (protein-bound) of rhodamines. In this review, we present the mechanism and design strategies of these fluorogenic and cell-permeable rhodamines, as well as their applications in bioimaging and biosensing.
荧光显微镜技术的进步为观察蛋白质并揭示其在活生物系统中的功能开辟了新的机会。小分子有机染料具有出色的光物理性质、较小的尺寸和高的光稳定性，可用作蛋白质成像中的强大荧光报告分子。然而，由于常规有机染料的细胞通透性不足和背景信号高，用其实现高对比度的活细胞标记靶蛋白仍然是生物成像和生物传感中的一个重大挑战。在过去的十年中，已经开发出了新一代的生色团和细胞通透性染料，通过精细调节罗丹明的细胞通透性、非荧光螺环状态（未结合）和荧光两性离子（蛋白质结合）之间的可逆平衡，极大地改善了活细胞蛋白标记。在这篇综述中，我们介绍了这些生色团和细胞通透性罗丹明的机制和设计策略，以及它们在生物成像和生物传感中的应用。
