Surface-Modified Nanozymes for Enhanced and Selective Catalysis

Surface-modified catalytic nanoparticles (nanozymes) are introduced as hybrid nanoparticles overcoming basic limitations associated with bare nanozymes that include moderate catalytic turnovers, lack of substrate selectivity and chiroselectivity, and poor or nonselective permeabilities into biomembrane. This review introduces aptamer-modified nanozymes, receptor (cyclodextrins)- or ligand (amino acids, peptides)-functionalized catalytic nanoparticles, and molecularly imprinted polymer-coated nanozymes as hybrid frameworks improving the catalytic properties and selective/chiroselective functions of the nanozymes. Binding of the reaction substrates to the aptamers, ligands, or molecular-imprinted sites, by affinity interactions, concentrates the substrates in spatial proximity to the nanozyme catalytic sites ("molarity effect"), thereby enhancing the catalytic performance of the frameworks. Specific and chiroselective binding interactions of the substrates to the surface modifiers lead to selective or chiroselective chemical transformations. Moreover, by appropriate molecular engineering of the surface modifiers on the nanozymes, catalytic functions lacking in the parent bare nanozymes are demonstrated. Potential applications of surface-modified nanozymes are discussed.