Long wavelength emission two-photon fluorescent probe for highly selective detection of cysteine in living cells and inflamed mouse model
As a semi-essential proteinogenic amino acidand biothiol, cysteine (Cys) is highlyimportant in many basic cellular processes. Several two-photon (TP) fluorescent probes for Cys detectionhave been developed, but they are still far away from the practical application due to the relative short wavelength (<600 nm) and poor selectivity. To this end, enhancing the selectivity of TP probes for detecting Cys over other biological thiols is urgently demanded.Herein, we developed a long-wavelength emission TPactivatable fluorescent probe (ACP) for detecting Cys with high sensitivity utilizing the hydroxyl protection/deprotection strategy, in whichACP can preferentially react with Cys to form a red-emitting anthocyanidin derivative fluorophore. TP fluorescence imaging of Cyswith ACP at the cellular and tissue levels have been successfully carried out with excellenttissue penetration. More importantly, the fluctuation of Cys inendotoxin lipopolysaccharide (LPS) induced oxidative stress mouse model could also been successfully visualized. Therefore, ACP has shown great potential to investigate the roles of Cys in the biological and medical study.