Using maleimidoethylmonoamide cysteine (Fmoc)(StBu) (1) as a medium, cysteineresidues on proteins of chicken eggshell membrane (ESM) were successfully converted into N-terminal cysteines. After a biocompatiblecondensationreaction between the N-terminal cysteine and fluorescent probe 2-cyanobenzothiazole-Gly-Gly-Gly-fluorescein isothiocyanate (2), a new fluorogenic structure luciferin-Gly-Gly-Gly-FITC