Reversible fluorescent probes for biological dynamic imaging: Current advances and future prospects

Reversible fluorescent probes have attracted the attention of researchers because of their ability to repeatedly observe the dynamic changes of multi-biomolecules in real-time and in situ. In recent years, fluorescent probes have been wildly used in numerous biological research, among them, the reversible fluorescent probes, resemble based on changes of pH and based on spiral cyclization, have played an important role in the research on biomolecular interactions, which deepened our understanding of the activity of cell life. Although fluorescent probes with reversible processes have been used in real-time to visualize the dynamic changes inside cells for an extended period, however, the lack of a systematic review of this fascinating subject has severely hindered the design and the application of such reversible fluorescent probes for the in-depth understanding of the relationship between the various substances that change during the operation of cells. In this review, we have divided reversible fluorescent probes into six categories for the first time, according to the basic principles of reversible reactions, and focus on the interactions revealed by reversible fluorescent probes between various physiological compounds and small molecules compounds or microenvironmental levels. In order to grasp the topic clearly and intuitively, this paper reviewed the representative example of reversible fluorescent probes in bioimaging also from the chemical perspectives of complex reactions, addition reactions, redox reactions, spiral cyclization, etc. Several representative examples of each reaction were reviewed, all of which demonstrate that reversible fluorescent probes could be powerful tools for visualizing intracellular dynamic changes in real-time. In addition, the existing problems and future challenges in the biological application of reversible fluorescent probes were discussed from multiple angles. This evaluation will aid in creating and enhancing innovative reversible fluorescent probes and serve as a resource for future research into life events.