Microenvironment-Engineered Biocatalytic Metal-Organic Framework Nanomotors for Selective and Transformative Water Decontamination.

Catalytically powered micro-/nanomotors have become a compelling alternative to conventional catalysts for active and efficient removal of environmental pollutants in water remediation. We developed a novel biocatalytic nanomotor system by encapsulating catalase and peroxidase enzymes into metal-organic frameworks (MOFs), demonstrating exceptional speed and facilitated motion-induced convection and mass transfer. Leveraging a synergistic structural etching and surface engineering strategy using tannic acid (TA), we create a tailored microenvironment of the MOF's framework with charge-selective and nanoconfinement properties. Both experimental and simulation results indicate that microenvironment modulation of MOF matrix could act in synergy with the encapsulated enzymes and significantly improve efficiency and selectivity in removing charged pollutants. Surface engineering of TA selectively preconcentrates target contaminants by modulating the MOF shell's surface charge, while etching-induced voids facilitate rapid mass transfer to the enzyme active sites. Finally, we also validated the applicability of these nanomotors in the transformative removal of pollutants from the aqueous phase into polymeric products via an enzyme-mediated polymerization pathway. This biocatalytic nanomotor system provides a promising water remediation paradigm for reducing carbon emissions and recycling chemical energy from emerging contaminants.