Adhesive bacterial amyloid nanofiber-mediated growth of metal-organic frameworks on diverse polymeric substrates

The development of a simple, robust, and generalizable approach for spatially controlled growth of metal-organic frameworks (MOFs) on diverse polymeric substrates is of profound technological significance but remains a major challenge. Here, we reported the use of adhesive bacterial amyloid nanofibers, also known as curli nanofibers (CNFs), major protein components of bacterial biofilms, as universal and chemically/mechanically robust coatings on various polymeric substrates to achieve controlled MOF growth with improved surface coverage up to 100-fold. Notably, owing to the intrinsic adhesive attributes of CNFs, our approach is applicable for MOF growth on both 2D surfaces and 3D objects regardless of their geometric complexity. Applying this technique to membrane fabrication afforded a thin-film composite membrane comprising a 760 ± 80 nm ZIF-8 selective layer grown on a microporous polyvinylidene fluoride (PVDF) support which exhibited a C₃H₆/C₃H₈ mixed-gas separation factor up to 10, C₃H₆ permeance up to 1110 GPU and operational stability up to 7 days. Our simple yet robust approach therefore provides new insights into designing new interfaces for mediating MOF growth and opens new opportunities for constructing new MOF-based membranes and devices.