Direct Fabrication of COF Microreactors From Pickering Droplets for Efficient Enzymatic Catalysis and Photobiocatalytic Cascade

ABSTRACT Advancing enzyme immobilization techniques with desired catalytic activity, industrial productivity, and synergistically integrated specialties for potential cascade catalysis is urgently demanded to extend biosynthesis in vitro. Herein, we present a versatile surfactant‐assisted Pickering emulsion interfacial polymerization strategy to fabricate enzymatic covalent organic framework (COF) microreactors, in which a crystalline and crack‐free COF layer is grown directly on Pickering droplets with the aid of surfactant molecules. The thus‐designed microreactors not only feature a capacious confined space for enzyme packaging but also possess a permeable shell for regulating molecular transportation, enabling enzymatic biocatalysis with high efficiency. As proof of concept, we demonstrate significantly enhanced catalytic activity and impressive long‐term durability (200 h) for lipase‐catalyzed kinetic resolution of racemic alcohols. Meanwhile, we find that the catalytic activity of encapsulated enzymes can be finely manipulated by engineering the functional group of COF skeletons. Furthermore, the highly crystalline architectures also empower the microreactors with excellent photocatalytic activity for the generation of H 2 O 2 , rendering an integrated photoenzymatic cascade system that exhibits 1.39–6.57‐fold higher efficiency in alkene epoxidation than conventional immobilized systems or physically mixed counterparts. This work provides a reliable way to make high‐performance biomolecule‐in‐COFs and delivers guidance for designing sophisticated microreactors for practical biocatalysis applications.