The near-infrared fluorescent probes based on phenoxazine for the rapid detection of hypochlorous acid

Hypochlorous acid (HOCl) is tightly related with a series of diseases, and plays an important part in biological processes. Herein, we designed and synthesized two “turn-on” near-infrared (NIR) probes (BC-2 and BC-3) based on phenoxazine to sense and image HOCl both in vitro and in vivo. In the presence of HOCl, the fluorophore phenoxazine was released and the fluorescence intensity significantly increased. The probes show excellent selectivity, high sensitivity, and rapid response towards HOCl. Moreover, the probe BC-3 is capable of rapidly detecting endogenous HOCl in living cells and in the inflammation area from the mouse models of arthritis.