Cucurbituril–Gold Nanoparticle Assemblies for Aqueous Oxime Formation Catalysis

Efficient substrate binding and spatial organization are critical for enzyme-like catalysis. This study examines a nanoparticle-based catalytic platform in which cucurbit[7]uril macrocycles are integrated into negatively charged gold nanoparticle monolayers. The resulting supramolecular constructs, referred to as “suprazymes,” catalyze the formation of oximes from aldehydes and hydroxylamine in water. By systematically varying substrate charge, size, and structure, as well as nanoparticle curvature and monolayer composition, we identify key structural features that influence catalysis. A suprazyme with phosphonate-terminated ligands achieves an over 2400-fold rate acceleration relative to the uncatalyzed reaction. These findings reveal design principles for engineering advanced nanoparticle-based enzyme mimics and provide a framework for their development.