Design of a ratiometric two-photon probe for imaging of hypochlorous acid (HClO) in wounded tissues

Abstract

HClO plays crucial roles in a wide range of biological and pathological processes. Recent studies have revealed that the generation of HClO has close links with the wound healing process. It's thus meaningful to develop a reliable method for monitoring HClO in wounded tissues. Toward this purpose, we herein report a rationally designed quinolone-based ratiometric two-photon fluorescent probe, <b>QClO</b>, for HClO. The probe <b>QClO</b> rapidly displays a drop in blue emission and an increase of green emission in response to HClO due to the oxidation of oxathiolane. The fluorescence intensity ratio (green/blue) can serve as the ratiometric detection signal for HClO with high sensitivity. After confirming its excellent sensing performance <i>in vitro</i>, the probe was validated by detecting exogenous and endogenous HClO in living cells. The probe was capable of monitoring HClO <i>in situ</i> in the wounded tissues of mice by two-photon microscopy, which demonstrated the production profile of HClO during the wound-healing process. This work affords a simple and reliable tool for the detection and imaging of HClO, which promises to find more applications in HClO-related biological and pathological studies.