Ultrafast responsive near-infrared fluorescent probe for the detection of hypochlorous acid and its bioimaging applications in living cells and inflammatory mice.

Abstract

Hypochlorous acid (HClO), as a key reactive oxygen species (ROS), plays a crucial role in diverse physiopathological processes. Consequently, the development of reliable methods for HClO detection in living systems is of considerable significance. Fluorescent probes with excitation and emission in the near-infrared (NIR) region offer substantial advantages for bioimaging owing to deep tissue penetration, reduced background autofluorescence, and minimal photodamage to biological specimens. In this work, we present a novel NIR fluorescent probe, JL-1, derived from a hemicyanine scaffold. Upon reaction with HClO, the probe exhibits a strong NIR emission peak at 780 nm when excited at 685 nm. JL-1 demonstrates not only high sensitivity, with a detection limit as low as 31 nM, but also excellent selectivity toward HClO over various competing analytes. Furthermore, the probe enables an ultrafast fluorescence response (4 s) to HClO. Taking advantage of these favorable attributes, JL-1 has been successfully utilized to visualize intracellular HClO and monitor its fluctuations during cisplatin-induced apoptosis. Moreover, it was further applied to visualize HClO changes in inflamed living mice. Collectively, these features establish JL-1 as an effective tool for elucidating the roles of HClO in HClO-related physiological and pathological processes.