LAUSR

Abstract Carbazole derivatives have been receiving extensive attention owing to the merits of favorable donor ability, good planarity, rich photophysical properties, and excellent biocompatibility. In recent years, carbazole-based small molecular fluorescent probes have developed rapidly and extensively utilized for bioimaging, providing abundant and valuable information for studying important life processes. Although the topic of carbazole-based fluorescent probes for bioimaging is important and frontier, no review focused on this hot subject so far. Thus, in this tutorial review, we firstly summarize and highlight the recent advances in design, photophysical properties, and biological applications of carbazole-based probes. In order to legibly and intuitively grasp the topic, this work was classified into five parts according to the sensing targets detected by carbazole-based probes. Accordingly, we provide an overview of recent advances of carbazole derivatives for bioimaging in the perspective of biological applications of the carbazole chemosensors toward ionic species, reactive sulfur species (RSS), reactive oxygen species (ROS), biomacromolecules, microenvironment and others. Several representative examples for each bio-application have been reviewed, and all these cases demonstrate that carbazole derivatives could act as a robust tool for monitoring biomolecules in living systems. Moreover, with the assistance of fluorescence imaging, some carbazole-based probes can be employed to feedback the subtle concentration changes of biomarkers at the disease sites, greatly facilitating the significant advances in cell biology and medical diagnostic imaging. In addition, we also discuss the unsolved problems and future challenges in the terms of synthesis and biological application of carbazole derivatives. Future attention should be focused on the designing carbazole-based probes involving near-infrared emission and multiple sites to improve detection efficacy and provide more biological information. More importantly, great effort and collaboration from different communities of chemists, physicists and biologists are required to translating laboratory feasibility of carbazole derivatives to clinical practicability. This review herein will promote new progress and improvements of novel carbazole-based probes for further exploring life events.