Fe3O4@Phe@Lipase Floating Microspheres Accelerate Oil-Water Interfacial Catalysis

While lipases offer an environmentally friendly and highly efficient means of degrading lipids and mitigating waterborne lipid pollution, the practical application of free lipases in industrial settings is often limited by inherent instability and dependence on oil-water interfaces for activation. To address these limitations, this study presents an innovative strategy based on the synthesis of phenylalanine-modified magnetic nanoparticles (Fe₃O₄@Phe), which leverages hydrophobic-electrostatic synergistic interactions to achieve high lipase loading and stable immobilization. The hydrophobic phenylalanine moiety of Fe₃O₄@Phe is specifically designed to mimic the oil-water interfacial microenvironment, thereby enhancing catalytic efficiency. Furthermore, we ingeniously employed hollow microsphere-integrated 3D printing to fabricate Fe₃O₄@Phe@Lipase Floating Microspheres, enabling precise positioning of the immobilized lipase at the oil-water interface and resulting in a 1.86-fold increase in reaction efficiency compared to non-floating Fe₃O₄@Phe@Lipase. Importantly, the Fe₃O₄@Phe@Lipase Floating Microspheres demonstrated exceptional stability to a wide range of extreme conditions, including varying pH levels, elevated temperatures, and denaturants. These characteristics render them well-suited for scalable applications in lipid contamination remediation in aquatic environments and industrial lipid hydrolysis, without requiring mechanical agitation or emulsification. This research not only demonstrates a promising strategy for enzyme immobilization on amino acid-functionalized magnetic nanoparticles through microenvironment mimicry, but also introduces a flexible assembly platform for tuning catalyst density and enhancing catalytic efficiency. The described method holds significant potential for broader application across a spectrum of interfacial reactions and with diverse catalysts in lipid pollution control.