Ice-mediated interfacial membrane synthesis of cargo-independent microcapsules

Abstract

Membrane-defined compartmentalization enables selective transport and protects biomacromolecules in living systems, yet synthetic microcapsules remain difficult to fabricate because existing methods are often harsh, multistep or cargo-specific. Here we report an ice-mediated interfacial reaction platform that programmes membrane growth on ice-sphere templates to generate closed microcapsules with cargo-independent encapsulation. During ice recrystallization, monomers preloaded within the ice matrix are enriched into the quasi-liquid layer, where they undergo confined interfacial amidation with a complementary organic-phase monomer to form a conformal polyamide membrane. Melting the ice releases intact microcapsules with encapsulated cargo retained. The resulting microcapsules exhibit tunable membrane thicknesses (7–260 nm) and diameters (30–500 μm), and function as confined microreactors for multienzyme redox cascades, achieving up to an 80-fold enhancement in visible-light-driven CO2-to-methanol conversion. This strategy provides a mild and potentially scalable route to programmable semipermeable microcompartments.