18-Naphthalimide derivative dyes targeting live cell mitochondria with large stokes shift

摘要

An ideal fluorescent dye for staining cell organelles should have multiple properties including specificity, stability, biocompatibility and a large Stokes shift. Tuneable photophysical properties enable 1,8-naphthalimide to be an excellent fluorophore in biomedical applications. Many naphthalimide derivatives have been developed into drugs, sensors and other dyes. In this study, a series of 1,8-naphthalimide derivatives targeting live cell mitochondria were synthesized. Among these probes, Mt-4 was characterized as the best one with highly specific mitochondrial localization, low cytotoxicity and large Stokes shift. More importantly, Mt-4 stood out as a potential mitochondrial dye for living cell experiments with induced mitochondrial stress from treatments since Mt-4 has enhanced fluorescence while undergoing mitochondrial stress.