A phenothiazine coumarin based ratiometric fluorescent probe for real-time detection of lysosomal hypochlorite in living cell and zebra fish

Hypochlorite (ClO-), a type of reactive oxygen species (ROS), plays an essential role in complex biological systems. Real-time detection of the content and distribution of ClO- in cells or subcellular organelle is critically essential. In this paper, a lysosomal-targeted fluorescent probe, Cou-Lyso, was constructed for real-time detection of ClO- in a ratiometric manner, achieving high sensitivity with a low detection limit (0.58 mu M). Upon reaction with ClO-, this probe was subjected to a significant fluorescence change from red emission (lambda(max)em = 610 nm) to green emission (lambda(max)em = 535 nm) with the ratio of I-535 (nm)/I-610 nm displaying a 76-fold enhancement from 0.04 to 3.03. The confocal imaging experiments for Cou-Lyso showed that this probe could detect ClO- in living cell and zebra fish. This probe has been successfully applied to stain lysosome and image lysosomal ClO- based on co-localization imaging experiments. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A lysosomal-targeted fluorescent probe Cou-Lyso was developed for real-time detection of ClO- in cells, showing high sensitivity and low detection limit. Confocal imaging experiments demonstrated that this probe could detect ClO- in living cells and zebra fish, providing a promising tool for studying ClO- in complex biological systems.