A novel fluorescent probe for rapidly detection cysteine in cystinuria urine, living cancer/normal cells and BALB/c nude mice.

Cysteine (Cys), an important organic small molecule containing sulfhydryl groups, plays paramount functions in human pathologies and physiologies. The detection of Cys in living vivo is essential for studying its roles. Here, we designed and synthesized a novel red-emission fluorescent probe AXPI-Cys with highly sensitivity (LOD = 48.9 ± 0.23 nM), rapidly response (<7 min) and colorimetric for detection cysteine. More importantly, the AXPI-Cys was determined Cys in real cystinuria urine samples for the first time with the satisfactory results (92%-99.96%) and employed for specifically location of endogenous/exogenous Cys in living cancer/normal cells and almost non-toxic, that is very valuable for diagnosis of cystinuria and observation of the distribution of Cys in normal cells. Notably, the AXPI-Cys was applied to imaging Cys in BALB/c nude mice with good biocompatibility and desirable tissue-penetration depth. Owing to the superior capability of AXPI-Cys, it provided a desired method to detect Cys in urine samples and cells, and exhibited munificent potential usage in biosystems and imaging studies in vivo.