Heteroepitaxial growth of Au@Pd core-shell nanocrystals with intrinsic chiral surfaces for enantiomeric recognition

Noble metal surfaces with intrinsic chirality serve as an ideal candidate for investigating enantioselective chemistry due to their superior chemical durability and high catalytic activity. Recently, significant advance has been made in synthesizing metal nanocrystals with intrinsic chirality. Nonetheless, the majority reports are limited to gold. Herein, through a heteroepitaxial growth strategy, the synthesis of metal nanocrystals with intrinsic chirality to palladium was extended for the first time and their application in enantioselective recognition was demonstrated. The heteroepitaxial growth strategy allows for transferring the chirality of homochiral Au nanocrystals to Au@Pd core-shell nanocrystals. By employing the chiral Au@Pd nanocrystals as enantiomeric recognizing elements, a series of electrochemical sensors for chiral discrimination were developed. Under optimal conditions, the peak potential between D-dihydroxyphenylalanine (D-DOPA) and L-di-hydroxyphenylalanine (L-DOPA) is about 80 mV, and the peak current of D-DOPA is 2 times as much as that of L-DOPA, which enables the determination of the enantiomeric excess (EE, %) of L-DOPA. Overall, this report not only introduces a heteroepitaxial growth strategy to synthesize metal nanocrystals with intrinsic chirality, but also demonstrates the superior capability of integrating intrinsic chirality and catalytic properties into metal nanocrystals for chiral recognition.