Catalytically Active Hollow Fiber Membranes with Enzyme‐Embedded Metal–Organic Framework Coating

Metal–organic frameworks (MOFs) are suitable enzyme immobilization matrices. Reported here is the in situ biomineralization of glucose oxidase (GOD) into MOF crystals (ZIF‐8) by interfacial crystallization. This method is effective for the selective coating of porous polyethersulfone microfiltration hollow fibers on the shell side in a straightforward one‐step process. MOF layers with a thickness of 8 μm were synthesized, and fluorescence microscopy and a colorimetric protein assay revealed the successful inclusion of GOD into the ZIF‐8 layer with an enzyme concentration of 29±3 μg cm−2. Enzymatic activity tests revealed that 50 % of the enzyme activity is preserved. Continuous enzymatic reactions, by the permeation of β‐d‐glucose through the GOD@ZIF‐8 membranes, showed a 50 % increased activity compared to batch experiments, emphasizing the importance of the convective transport of educts and products to and from the enzymatic active centers. Passing through: Reported for the first time is the successful in situ biomineralization of an enzyme‐containing metal–organic framework (MOF) layer on a polymeric hollow fiber in a facile one‐step process. The interconnection between an enzymatic active layer and a porous membrane overcomes stability drawbacks, removes the need for MOF separation, and leads to increased enzyme activity as a result of the improved mass transport by permeation.