Effective Enzyme Coimmobilization and Synergistic Catalysis on Hierarchically Porous Inorganic/Organic Hybrid Microbeads Fabricated Via Droplet‐Based Microfluidics

In this paper, a novel and robust droplet‐based microfluidic method to fabricate poly(ε‐caprolactone)/silica (PCL/SiO₂) hybrid microbeads with hierarchically porous architecture is described and their performance as multienzyme carriers for cascade catalysis is further investigated in detail. In addition to the precise control on size and monodispersity of PCL/SiO₂ microbeads enabled by the microfluidic method, the presence of ammonia as a catalyst for the hydrolysis and condensation of tetraethylorthosilicate makes it possible to manipulate the competition between sol–gel process and solvent extraction and thus adjust the surface porosity of hybrid microbeads, which eliminates the use of porogens/templates and also the complicated post‐treatment. Isothiocyanate‐immunoglobulin G/cyanine 3‐bovine serum albumin (FITC‐IgG/Cy3‐BSA) and superoxide dismutase/chloramphenicol acetyltransferase (SOD/CAT) are coimmobilized, respectively onto hierarchically porous PCL/SiO₂ hybrid microbeads via either physical adsorption or covalent binding. Fluorescence intensity of coimmobilized FITC‐IgG/Cy3‐BSA proves that the proteins/enzymes immobilization amount via covalent binding is much higher than physical adsorption. The enhanced enzymatic activity, total antioxidant capacity, and reusability assay reveal that coimmobilized SOD/CAT exhibits better performance compared with the mono‐immobilized ones, mainly due to their mutual synergistic effect. The excellent results achieved in the work indicate that hierarchically porous PCL/SiO₂ hybrid microbeads are very promising carriers for multienzymatic catalysis.