Jie Shi

The burgeoning demand for efficient multienzyme cascades necessitates advanced scaffolds capable of precise spatial organization; however, constructing heterostructured multilayer frameworks (HMFs) remains a formidable challenge due to harsh solvothermal conditions and imprecise enzyme localization. Herein, a biocompatible, interface-directed strategy is reported to engineer a cell-mimetic metal–organic framework@covalent organic framework (MOF@COF) heterostructure as a versatile colorimetric biosensing platform. Specifically, glucose oxidase immobilization within defect-rich (COOH)2-UiO-66 via competitive coordination generated robust sensing elements. Subsequently, ionic liquid-catalyzed interfacial nucleation orchestrated the in situ growth of a horseradish peroxidase-encapsulated COF shell, yielding a compartmentalized architecture with hierarchical channels. Mechanistic investigations and density functional theory (DFT) calculations reveal that the support’s defect density and interfacial adsorption energy, rather than long-range crystallinity, dictate the directional assembly of the COF layer. This heterostructure exhibits enhanced cascade activity and analytical reliability through spatial proximity and reduced mass transfer resistance over conventional one-pot or stepwise assemblies, while control studies with zeolitic imidazolate framework-8 and hydrogen-bonded organic framework counterparts underscore its superiority in proximity-induced intermediate transfer. Integrating monomer reactivity with topological symmetry offers a predictive blueprint for customizing structurally diverse HMF libraries. Ultimately, flexible replacement of the core enzyme enables the functional validation of this platform through the colorimetric quantification of glucose and hypoxanthine, offering a rational blueprint for engineering biointerfaced heterostructures in cascade biocatalysis.

A size-matched magnetic core-shell platform (Fe₃O₄@MnO₂@mSiO₂) was constructed for immobilizing Candida rugosa lipase (CRL). The flower-like MnO₂ interlayer provides chemical shielding, while mesoporous channels were expanded to 6.45 nm to geometrically match CRL (approximately 5 nm). Driven by interfacial activation, the support exhibited a selective purification effect, achieving a high activity-based immobilization yield (85.2%) and protein loading (143.1 mg g^-1). The immobilized specific activity reached 31.4 U mg^-1 (1.57-fold higher than the free enzyme) with 88.2% recovered activity. Crucially, in the sterically demanding esterification of phytosterols, the biocatalyst achieved 84.33% maximum conversion at 50 °C within 40 h. Furthermore, the rigid silica walls exerted a spatial "cage effect" that locked the enzyme active conformation, conferring exceptional thermal stability and reusability. This hierarchical support design offers a robust solution for macromolecular industrial biocatalysis.

A novel emulsion‐induced interfacial assembly strategy was developed to synthesize hollow mesoporous carbon spheres (HM‐Cs) using the unique synergistic effect among the F127/P123 composite soft templates, pore‐expanding agent (TMB), and the carbon precursor (dopamine). The synthesis conditions were optimized by adjusting the P123/F127 mass ratio (19:1), carbonization temperature (550°C), and heating rate (2.5°C/min), resulting in HMC with well‐defined hollow cavities (150 nm) and radial mesopores (13‐20 nm). Characterizations via SEM, TEM, FTIR, TGA, XPS, and BET confirmed the material structural integrity, nitrogen doping, and high specific surface area (72.26 m ² /g for HM‐C550). When used as carriers for Candida rugosa lipase (CRL) immobilization, HM‐C550 achieved a high protein loading capacity (127.58 mg/g). The immobilized lipase (HM‐C550@CRL) exhibited superior thermal stability and reusability compared to free CRL, retaining 34.08% of its activity after six hydrolysis cycles and 53.29% after six esterification cycles (cumulative activity 4.31 times that of the free enzyme). In the biosynthesis of phytosterol esters, optimal conditions (n‐hexane solvent, 40°C, 50 h, 20% enzyme dosage, 1:2 substrate molar ratio) yielded a maximum esterification rate of 76.99%. This work provides a controllable approach to fabricate functional carbon‐based carriers, advancing their application in efficient biocatalysis for functional lipid biosynthesis.

Cascade reactions integrating biocatalysis and chemical catalysis have gained extensive attention but are limited by enzyme instability, poor carrier-enzyme compatibility, and mass transfer barriers. Herein, we report a novel polymer-assisted heterogeneous epitaxial growth strategy to fabricate hollow covalent organic framework (COF) capsules (HNKCOF-98), using ZIF-8 as a sacrificial template. Dual modification of ZIF-8 with polyvinylpyrrolidone (PVP) and branched polyethylenimine (BPEI) is critical, where BPEI provides amino sites for COF heterogeneous nucleation while PVP enhances dispersion and suppresses disordered fibrous growth by regulating monomer orientation. After removing the ZIF-8 core, HNKCOF-98 capsules with high crystallinity and specific surface area (1623 m²/g) are obtained. These capsules efficiently immobilize enzymes, maintaining their conformational flexibility and activity. The GOX&HRP@HNKCOF-98 cascade system exhibits excellent performance in glucose detection, with high stability and selectivity. Additionally, the XOD@HNKCOF-98@Pt biomimetic reactor achieves sensitive xanthine detection. This work expands COF morphological diversity and provides a versatile platform for high-performance enzyme immobilization and biosensing.

Magnetic mesoporous materials, integrating magnetic nanoparticles and mesoporous structures, have great potential in biomedicine, catalysis, and the environment. This study develops a novel core-shell nanocarrier (CS-WMM: magnetic core-flower-like MnO₂ mesoporous layer-silica shell) for efficient lipase immobilization and enhanced phytosterol esters synthesis. Via a surfactant-free kinetic-controlled interfacial assembly, walnut-like dual-mesoporous microspheres (inner flower-like MnO₂, outer mesoporous SiO₂: 4.8 nm pore, 158.61 m²/g surface) are constructed, enabling a high enzyme loading (210 mg g^-1) and improved substrate diffusion. Compared with Fe₃O₄@MnO₂, CS-WMM achieves 78.33% esterification conversion and retains 55.03% activity after 7 cycles via dual-mesoporous synergy. This work provides a novel material design strategy with high loading capacity and structural stability for hydrophobic substrate-driven biocatalytic systems, which holds potential applications in food lipid processing, biopharmaceuticals, and other fields.