Multifunctional integrated compartment systems for incompatible Pickering interfacial catalysis cascade reactions based on responsive core–shell nanoparticles

Abstract

Chemoenzymatic cascade reactions can expand the scope of single catalytic reactions, offering methods for reducing the production isolation steps, downstream processing costs, and reaction equilibria transformation times. However, combined cascade chemo- and biocatalysis is challenging due to the incompatibilities, reagent insolubilities and destructive interference of one or more catalytic species. To address this challenge, we herein report a method for the generation of smart responsive core–shell microreactors via superficial growth of a responsive protein crust around mesoporous nanoparticles, elucidating novel strategies for incompatible cascade reactions. The resulting core–shell structures regionally host metal and biological catalysts to create multifunctional, integrated one-pot microreactors for cascade Pickering interfacial catalysis (PIC). We demonstrate this feature in a protein shell enzyme by providing different active sites in nanoconfined volumes for efficient Pickering emulsion methylphenyl sulphoxide production. The first step occurs at the mesoporous core, in which glucose oxidase oxidizes glucose to generate H₂O₂, and the subsequent steps occur on the interface shell, where NaCas–AuCNs facilitate the SO bond formation on methylphenyl sulfite at a sufficiently high H₂O₂ concentration and nanoconfinement. The core–shell structure responsiveness allows catalyst recovery, enabling the products to be easily separated via external stimulation after the reaction, thus simplifying post-treatments. In addition, we extend our findings to other functional core–shell systems, validating the facile generation, versatility and expandability of the developed strategy.