Development of an endoplasmic reticulum-targeting fluorescent probe for the two-photon imaging of hypochlorous acid (HClO) in living cells

Abstract

As an important reactive oxygen species, hypochlorous acid (HClO) could irreversibly destroy Ca²⁺-ATPase to inhibit Ca²⁺ transport in the endoplasmic reticulum (ER), which may eventually lead to cell dysfunction and cell death. Herein, we present a novel ER-targeting fluorescent probe (NHS-ER) for the two-photon detection of HClO in living cells. NHS-ER was constructed using naphthalimide and showed strong green fluorescence. In response to HClO, the fluorescence intensity at 502 nm gradually decreased, and the probe showed excellent selectivity to HClO over other biologically relevant ROS. Moreover, the probe NHS-ER showed ER-targeting properties and could be successfully applied to the two-photon imaging of HClO in living cells.