Three-dimensional ordered macroporous MOF-based smart gating membrane with size screening effect and aptamer specificity for highly efficient thrombin isolation

Membrane separation is an efficient technique for the separation and extraction of biomolecules from complex matrices. Herein, a thrombin aptamer-functionalized temperature-responsive smart gating metal-organic framework (MOF) membrane was fabricated by three-dimensional ordered macroporous ZIF-8 (3DOM ZIF-8) and copolymer of sodium alginate grafted with poly(N-isopropylacrylamide) (SA-PNIPAM) for thrombin (TB) isolation. The SA-PNIPAM on the exterior surface of 3DOM MOFs endows the membrane with favorable protein penetration selectivity via temperature-controlled size-screening effect, and the aptamer functionalized on the interior macropore provides excellent thrombin capturing specificity. The separation factor of the smart gating membrane ranges from 13.88 to 49.22 for mixtures of TB with other protein species, and TB enrichment factor is high up to 95.97 under a TB/HSA mass ratio of 1:1000. The aptamer functionalized smart gating membrane is applied to the selective isolation of TB from the human serum. Fibrin production tests demonstrate that the biological activity of the isolated TB is well maintained and suitable for ensuing applications. Moreover, this 3DOM MOF-based smarting gating membrane exhibits high fouling-resistance performance. [Display omitted] •A temperature responsive three-dimensional ordered macroporous ZIF-8-based membrane is designed and fabricated for protein separation.•The separation mechanism of the membrane includes size-screening effect of PNIPAM and specific high-affinity of aptamer towards thrombin.•The three-dimensional ordered macroporous ZIF-8-based membrane offers favorable separation factor, and achieves a thrombin enrichment factor high up to 95.97.•The three-dimensional ordered macroporous ZIF-8-based membrane provides superior thrombin adsorption capacity (60 U mg−1).•The membrane is applied to the isolation of trace thrombin from human serum , and the isolated protein maintain favorable biological activity.