Recent process in organic near-infrared fluorescent probes for detecting hypochlorous acid/hypochlorite

Hypochlorous acid (HClO) plays an essential role in physiological and pathological processes, Dysregulated HClO production has been implicated in various disease states. Consequently, in vivo HClO monitoring is crucial for elucidating disease pathogenesis. Among various detection strategies, near-infrared (NIR) fluorescent probes offer unparalleled advantages for bio-imaging. The design of NIR-HClO fluorescent probes has garnered increasing research focus. This review provides a critical evaluation of the latest advances (2021–2025) in the design and construction of organic NIR fluorescent probes for selectively monitoring HClO. We systematically emphasize four major recognition strategies based on the oxidation of carbon-carbon unsaturated bonds, chalcogenides, nitrogen-containing groups, and phenol analogues. Furthermore, we offer a comprehensive discussion on the overarching challenges in the field, including the delicate interplay between fluorophore stability and recognition moiety reactivity, the trend towards multifunctional and theranostic probes, and the formidable quest for activatable probes in the second near-infrared (NIR-II) window. Finally, we outline future prospects, aiming to inspire innovative designs that will overcome current bottlenecks and propel the field towards clinical translation. We believe that the continued development of advanced NIR fluorescent probes remains a prominent and vital trend for future research in chemical biology and diagnostics.