Biomimetic transmembrane transport of multi-enzymes to fabricate heterogeneous bioreactors with photoenzymatic reduction of CO2.

The cascade of bio-/chemo-catalysis with quantitative integration and optimal activity is vital for catalytic conversion, but highly challenging. Here, we innovate a co-immobilization strategy by mimicking cellular transmembrane transport using ionic covalent organic framework capsules (iCOFcap) to co-encapsulate multi-enzymes and chemocatalysts. Thanks to the swellable polyethylene glycol and the adjustable charge of iCOFcap shells, multi-enzymes can be adsorbed onto the iCOFcap shells and then transported stepwise into the inner cavity of iCOFcap by adjusting electrostatic interaction between the enzymes and iCOFcap. Thus, the iCOFcap enables both transmembrane transport multi-enzymes and one-pot pre-encapsulation of chemocatalysts to construct various cascade catalysts, enabling quantitative integration and nearly complete retention of enzyme activity. The formed heterogeneous cascade catalysts show excellent comprehensive performance for CO2 reduction with good reusability. Thus, this study presents a co-encapsulation strategy for bio-/chemo-catalysis, providing an energy-efficient alternative for biotechnological applications.