A hydrophilicity-based fluorescent strategy to differentiate cysteine/homocysteine over glutathione both in vivo and in vitro

An easily-prepared probe/nanogel composite indicator HTBNM/PU was presented, which showed selective fluorescence responses to cysteine/homocysteine over glutathione both in vivo and in vitro based on the different hydrophilicity of these biothiols. In principle, this approach could endow any lipophilic thiol indicator with selectivity for sulfur-containing amino acids.