Regioselective Growth of Mesoporous Metal–Organic Frameworks for the Construction of Anisotropic Nanohybrids

Mesoporous anisotropic nanohybrids (m-ANHs) have attracted growing interest because their structural asymmetry enables unique advantages in applications such as multidrug co-delivery and cascade catalysis. However, anisotropic growth in mesoporous systems has thus far been largely confined to an amorphous framework. Achieving regioselective growth of crystalline functional units integrated with mesoporous frameworks remains highly challenging, primarily because of the intrinsic competition at the heterointerface between crystal nucleation/deposition and micelle-directed mesostructural coassembly. Herein, we report an acidity-gated interfacial crystallization-coassembly switching strategy to construct single-crystalline mesoporous MOF (meso-MOF)-based ANHs. This strategy enables the site-selective growth of a new single-crystalline meso-MOF compartment at predefined heterointerfaces, yielding a diverse family of well-defined frame-like, dumbbell-like, and ternary spiny nanohybrids. Mechanistically, precise regulation of the HCl/CH3COOH ratio modulates the nucleation kinetics of MOF precursors, generating localized supersaturation that is sufficient to trigger site-selective heterogeneous nucleation. Concurrently, synchronization of MOF nucleation/growth with interfacial micelle-directed coassembly allows crystallization and mesopore organization to proceed cooperatively. The applicability of this interfacial regulation is demonstrated in several lattice-compatible and chemically stable MOF systems with different compositions and hybrid configurations. As a proof of concept, the hierarchical spiny topology significantly enhances physical bacteria–material interactions, endowing the ternary ANHs with superior antibacterial performance. Remarkably, even in the absence of any drug loading, the ANHs achieve an approximately 90% inhibition efficiency against drug-resistant bacteria. This work establishes a versatile route to regioselectively integrate single-crystalline mesoporous domains into complex anisotropic nanohybrids and highlights the functional potential of structurally programmed crystalline mesoporous interfaces.