Carrierless Immobilization Route for Highly Robust Metal–Organic Hybrid Enzymes

The absence of a universal enzyme immobilization method that fulfils the needs of each biocatalytic system has boosted the development of new approaches to the fabrication of heterogeneous biocatalysts. Herein, we present a protocol for the synthesis of a novel sort of catalytically responsive hybrid biomaterials, named metal-organic enzyme aggregates (MOEAs). The formation of MOEAs is triggered by the coordination of divalent metal cations to imidazole-decorated enzyme nanogels in a fast and effective assembly mechanism. The size and morphology of MOEAs can be tailored from small individual particles to macroscopic aggregates, which are stable in water and disassemble in the presence of a complexing agent. Finally, the extensive compositional and catalytic characterization of the hybrids showed high transformation rates, significant protein loads, and great thermostability. These features revealed MOEAs as an excellent alternative as carrierless immobilization system.