A high-stable and fast-responsive lysosome-targeted probe for detection of endogenous and exogenous HClO in living cells and its application in zebrafish imaging

Abstract

HClO plays a vital role in the process of lysosome degradation of harmful substances within cells, thus it is urgently needed to develop a powerful imaging tool for detecting HClO in lysosomes. Herein, morpholine was introduced into 1,8-naphthoimide fluorophore as a lysosome targeting unit, and the 3-position of naphthalimide was modified with oxime moiety (CNOH) to synthesize a probe Nap-HClO for the detection of lysosomal HClO. The detection of HClO by Nap-HClO had been studied through theoretical calculations, which well verified the sensing mechanism of the probe. A comparison between the calculation results and experimental data revealed a close correlation between the two, indicating that Nap-HClO possesses theoretically predictable properties for HClO detection. In experiments on endogenous and exogenous HClO in cellular lysosomes, as well as exogenous HClO in zebrafish, Nap-HClO successfully monitored HClO. Nap-HClO exhibited high selectivity, rapid response (<1 min), low detection limit (∼6.8 × 10−6 M), and excellent stability in HClO detection, making it an excellent tool for detecting lysosomal HClO in organisms.