A Cys-regulated two-photon lysosomal targetable fluorescent probe and its application for the diagnosis of kidney diseases

Cysteine (Cys) is a small-molecule amino acid containing sulfhydryl group , which play a crucial role in many physiological and pathological processes. Detection of Cys closely related to kidney disease is significant important to investigate its function in cells and disease diagnosis. In this work, naphthalimide was selected as fluorophore scaffolds to synthesize a novel lysosome-targeted fluorescent probe Cys-J for detection of Cys with excellent optical properties , quick response, simple synthesis, and good stability. In addition, the probe was able to release H 2 S with therapeutic potential in multiple diseases based on the recognition of Cys, so the novel Cys fluorescent probe Cys-J constructed is of value for therapeutic integration applications. Furthermore, Cys-J was successfully used to visualize the level of Cys under kidney diseases (nephritis and kidney injury) for the first time by two-photon fluorescence imaging which could be used as a potential image tool for further clinical diagnosis of kidney diseases. A new Cys-trigger two-photon lysosomal targetable fluorescent probe Cys-J was designed to diagnose kidney diseases. • The compound Cys-J is a new targeting lysosomal fluorescent probe . • The probe Cys-J exhibited low cytotoxicity to living cells, good anti-interference capacity and photo-stability. • In the presence of Cys, the probe Cys-J could release hydrogen sulfide, which may have potential anti-inflammatory effects. • The probe Cys-J could specifically target lysosome with a Pearson's coefficient of 0.90. • The probe Cys-J was first used for Cys detection in the nephritis and kidney injury .