Emerging near infrared fluorophore: Dicyanoisophorone-based small-molecule fluorescent probes with large stokes shifts for bioimaging

Dicyanoisophorone (DCI) has been used extensively as a quality acceptor for designing chemical sensors targeting different analytes, and developing a series of well-established DCI fluorophores with large Stokes shifts. As an emerging, powerful, and adaptable NIR fluorescence platform, DCI-based fluorescence probes are wildly being used in spectroscopy, biochemistry and medicine. This is the first review to focus solely on DCI-based fluorescent probes and classifies common DCI fluorescent platforms from reported probes, providing a comprehensive review of DCI-based small molecule fluorescent probes reported from 2018 to 2023. Among others, we discuss in detail the historical development of DCI fluorophores, synthetic methods, optical properties, and sensing mechanisms. Based on the classification of different analytes, the design strategies, and applications for detecting and visualizing in living organisms are systematically discussed. Finally, we present our perspective on the future developments and application of DCI-based fluorescent probes, and the challenges they face in current are also discussed. We hope that this review will provide new design ideas and strong theoretical support for the development of more powerful DCI-based fluorescent probes.