Recently,many efforts have been dedicated to creating enzyme-mimicking catalysts to replace natural enzymes in practical fields.Inspired by the pathological biomineralization behaviour of L-cystine,in this study,we constructed a laccase-like catalyst through the co-assembly of L-cystine with Cu ions.Structural analysis revealed that the formed catalytic Cu-cystine nanoleaves (Cu-Cys NLs)possess a Cu(Ⅰ)-Cu(Ⅱ) electron transfer system similar to that in natural laccase.Reaction kinetic studies demon-strated that the catalyst follows the typical MichaelisMenten model.Compared with natural laccase,the Cu-Cys NLs exhibit superior stability during long-term incubation under extreme pH,high-temperature or high-salt conditions.Remarkably,the Cu-Cys NLs could be easily recovered and still maintained 76％ of their activity after 8 cycles.Finally,this laccase mimic was employed to develop a colorimetric method for epinephrine detection,which achieved a wider linear range (9-455 μmol· L-1) and lower limit of detection (2.7 μmol·L-1).The Cu-Cys NLs also displayed excellent specificity and sensitivity towards epinephrine in a test based on urine samples.