Self-assembly of a compartmentalized co-immobilized enzyme system for efficient conversion of CO₂ to formate

CA and FDH were respectively compartmentalized immobilized in different MOFs by self-assembly. • GDH was co-immobilized with FDH to facilitate in-situ cofactor regeneration. • The characterizations showed compartmentalized immobilized multi-enzyme was rationally constructed as designed. • This compartmentalized multi-enzyme system shows excellent CO 2 conversion efficiency. Multi-enzyme cascade systems provide an efficient route for CO₂ reduction and conversion into value-added products. Formate, as the first key product in CO₂ reduction, has attracted considerable interest. However, inefficient cofactor regeneration, limited enzyme stability, and mass-transfer constraints remain major challenges. Herein, a compartmentalized co-immobilized multi-enzyme system was rationally designed to enhance CO₂-to-formate conversion efficiency. Formate dehydrogenase (FDH) and glutamate dehydrogenase (GDH) were co-encapsulated within ZIF-L to enable localized cofactor regeneration and reduced diffusion resistance, while carbonic anhydrase (CA) was independently immobilized on DUiO-67 to facilitate CO₂ hydration and improve substrate availability. The two enzyme-loaded carriers were subsequently integrated via self-assembly strategy to construct a compartmentalized multi-enzyme cascade reactor. The resulting composite preserved the crystalline structure and morphology of the pristine carriers and exhibited a well-defined spatial distribution of CA, FDH, and GDH consistent with the design concept. The compartmentalized system achieved a significantly higher formate yield than free tri-enzyme systems and non-compartmentalized dual-enzyme immobilization. Compared with previously reported immobilized multienzyme platforms for CO₂ conversion, this strategy demonstrates superior catalytic efficiency. Moreover, the modular immobilized carrier coupled with cofactor regeneration is readily extendable to other cofactor-dependent redox cascade reactions, offering a scalable and cost-effective platform for CO₂ bioconversion. Download: Download high-res image (140KB) Download: Download full-size image