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 H2S 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.