Morphology-dependent intelligent biocatalysts with automatic functionality regulation for activity enhancement and controllable recycling

Enzyme-nanoMOFs, a very recent and emerging green biocatalyst, has been widely researched to pursue the improvement of enzyme stability. However, MOFs coating decreases substrate accessibility and possesses nanometer size, thus restraining enzyme activity and controllable recycling. Here, inspired by natural biomineralization, we created a morphology-dependent intelligent enzyme-nanoMOFs@aptamers biocatalyst via rationally in situ tailoring the morphology of enzyme-nanoMOFs for enhancing the combination of substrate aptamers. The resulting enzyme-nanoMOFs@aptamers nanoflowers achieved an on-demand tuning of functionality, where self-enriching substrate by substrate aptamers acted in synergy with nanoMOFs@aptamersbased enzyme mimics to significantly boost catalytic activity during biocatalysis. Moreover, after completing the catalytic reaction, easily magnetic separation and then competitive release to automatically start the cyclic catalysis were provided by automatic structure switch of aptamer-cDNA hybridization and aptamer-substrate binding. The degradation of BPA with laccase-Cu-3(BTC)(2) @P1 reached 4.4-fold improvement in the catalytic efficiency. Laccase-Cu-3(BTC)(2) @P1 could be controllably recycled to retain 76% initial activity after 8 catalytic cycles. These catalytic and recyclable performances were much better than laccase-Cu-3(BTC)(2). The combination of the unique morphology of enzyme-nanoMOFs and performance of aptamers brings hope for the industrial application of intelligent enzyme-nanoMOFs@aptamers systems.

Automated summary

Inspired by natural biomineralization, researchers have created a morphology-dependent intelligent enzyme-nanoMOFs@aptamers biocatalyst, which enhances substrate aptamers binding and catalytic activity through in situ tailoring of enzyme-nanoMOFs morphology. The resulting nanoflowers achieve on-demand tuning of functionality and enable automatic magnetic separation and cyclic catalysis through structure switch.