A colorimetric and ratiometric fluorescent probe for ClO− targeting in mitochondria and its application in vivo

Abstract

A colorimetric and ratiometric fluorescent probe PMN–TPP for imaging mitochondrial ClO⁻ was prepared. The selectivity of PMN–TPP was excellent and the detection would not be influenced by other ROS. The limit of detection (LOD = 3σ/slope) for ClO⁻ was evaluated to be 0.43 μM, suggesting the probe's high sensitivity to ClO⁻. For the biological applications, PMN–TPP performed well in detecting endogenous HClO in living RAW264.7 macrophage cells. A co-localization study employing Mito Tracker green revealed that PMN–TPP was specifically located in the mitochondria of living RAW264.7 macrophage cells. In the in vivo experiment, a nude mouse with acute inflammation stimulated by lipopolysaccharide (LPS) was employed. After injection of PMN–TPP, the fluorescence signal changed gradually in 30 min and then remained unchanged in the injection region, demonstrating that PMN–TPP could detect the endogenous HClO in living animals.