Stereoselective Nanozyme Based on Ceria Nanoparticles Engineered with Amino Acids.

Stereoselectivity towards substrates is one of the most important characteristics of enzymes. Amino acids, as cofactors of many enzymes, play important roles in stereochemistry. Herein, chiral nanozymes were constructed by grafting a series of d- or l-amino acids onto the surfaces of ceria (cerium oxide) nanoparticles. We selected the most commonly used drug for combating Parkinson's disease, that is, 3,4-dihydroxyphenylalanine (DOPA) enantiomers, as examples for chiral catalysis. Through detailed kinetic studies of cerium oxide nanoparticles (CeNPs) modified with different eight amino acids, we found that phenylalanine-modified CeNP was optimal for the DOPA oxidation reaction and showed excellent stereoselectivity towards its enantiomers. l-Phenylalanine-modified CeNPs showed higher catalytic ability for oxidation of d-DOPA, while d-phenylalanine-modified CeNPs were more effective towards l-DOPA. Taken together, the results indicated that stereoselective nanozyme can be constructed by grafting nanoparticles with chiral molecules. This work may inspire better design of chiral nanozymes.