Recyclable Biocatalytic Membranes Governed by pH‐Gated Supramolecular Switches

ABSTRACT The development of biocatalytic membranes is often hindered by the lack of recyclable carriers and platforms, as conventional systems require disposal upon enzyme inactivation. We address this critical issue by designing a smart supramolecular membrane platform by integrating interfacial polymerization with reversible host‐guest chemistry. A cross‐linked network was fabricated on a membrane via the reaction between trimesoyl chloride and β‐cyclodextrin (β‐CD). Enzymes were covalently functionalized with a pH‐responsive guest molecule, dansyl chloride, enabling their directional immobilization through host–guest complexation with the membrane‐bound β‐CD. This design features a supramolecular switch, where the binding strength is pH‐modulated, allowing for reversible enzyme loading and carrier regeneration. The resulting membrane achieves a high enzyme loading of 0.64 mg cm −2 and retains > 85% activity across multiple cycles. Its universality is proven by the effective immobilization of multiple enzymes, underscoring its potential as a versatile platform for sustainable biocatalysis.