Immobilization of laccase via adsorption onto bimodal mesoporous Zr-MOF

• A new bimodal micro-mesoporous Zr-metal organic framework was synthesized. • The force between the support and laccase relies on physical adsorption and aperturing. • The characteristics demonstrate good stability of the laccase-support and support. • The bimodal pores lead to high adsorption without inactivation. • The immobilized laccase shows better activity and a wider utilization range. A new bimodal micro-mesoporous Zr-metal organic framework (Zr-MOF, MMU) with a particle size of approximately 200 nm was synthesized. The Brunauer–Emmett–Teller (BET) surface area and pore diameter of the nanoscale MMU were 453.8 m 2 /g and 3.5–7 nm, respectively. Laccase was immobilized onto MMU via physical adsorption. This immobilized system exhibited a large adsorption capacity (221.83 mg/g), broad pH and temperature profiles, and better stability and repeatability than free laccase. Inactivation of the interaction between the overcrowded laccase at high concentration and pore plugging were not observed due to the secondary pore structure (3.5 nm). The immobilized laccase showed better stability under extreme conditions than free laccase. The activity of immobilized laccase after utilization 10 times remained at approximately 50%, and it remained at 55.4% of its initial activity at the end of 3 weeks of storage in an aqueous phase. The good stability and retention of enzymatic activity indicated that the bimodal mesoporous Zr-MOF is a good support for the immobilization of laccase.