A simple fluorescent probe for glutathione detection and its bioimaging application in living cells

This study aimed to develop a simple fluorescent probe for detecting glutathione (GSH) over cysteine (Cys) and homocysteine (Hcy). To this end, two fluorescent probes HPY1, 2 that used pyrazoline as the fluorophore and an acrylate group as the recognition group for thiols were designed and synthesized. HPY1, 2 possessed excellent sensitivity, high selectivity and great stability for detecting GSH. The detection limit of HPY1, 2 for GSH was found to be 2.06 x 10-7 M, 1.36 x 10-7 M respectively. The recognition mechanism of HPY1, 2 to GSH were studied by fluorescence change experiments, HRMS and DFT calculation, which elucidated that HPY1, 2 and GSH could undergo Michael addition reaction to generate strongly fluorescent addition products. Additionally, HPY1 was successfully applied to imaging of both endogenous and exogenous GSH in L929 cells based on its low cytotoxicity and good cell permeability. This wok indicated that HPY1, 2 have a great potential for application in detection of GSH.

Automated summary

This study successfully developed a simple fluorescent probe HPY1, 2 with high sensitivity, selectivity, and stability for detecting GSH. The recognition mechanism between HPY1, 2 and GSH was elucidated to involve Michael addition reaction, indicating great potential for application in GSH detection.