The construct of artificial nanocatalyts by simulating natural enzymes and thereby bringing new properties for practical applications is still a challenging task to date. In this study, chiral tetrapeptide (L-phenylalanine-L-phenylalanine-L-cysteine-L-histidine)-engineered copper nanoparticles (FFCH@CuNPs) were fabricated as an artificial peroxidase (POD). More interestingly, the nano-catalysts exhibited chiral identification function. In comparison with other nanocatalysts like L-cysteine-, L-histidine-, chiral dipeptide (L-cysteine-L-histidine)-, or chiral tripeptide phenylalanine-L-cysteine-L-histidine)-modified CuNPs, FFCH@CuNPs demonstrated a higher POD-mimetic catalytic activity in the 3,3 ',5,5 '-tetramethylbenzidine (TMB)-H2O2 system and stronger enantioselectivity in the recognition of 3,4-dihydroxy-D,L-phenylalanine (D,L-DOPA) enantiomers. Considering the strength difference between the intermolecular hydrogen bonding and the pi-pi interactions, the principle behind the chiral discrimination of D,L-DOPA was explored. Furthermore, contents levels of surface Cu2+ ions and hydroxyl radicals were found in the FFCH@CuNPs-D-DOPA-TMB-H2O2 system than in the FFCH@CuNPs-L-DOPA-TMB-H2O2 system. Based on these results, a protocol for distinguishing between D,L-DOPA enantiomers through colorimetric recognition was established. This study provides a new insight into design and fabrication of oligopeptides@CuNPs-based chiral nanozymes with improved catalytic performance and features additional to those of natural enzymes.
