Dimensional Assembly Engineering of Ce‐MOF Interfaces for Selective Recognition of Phytic Acid

ABSTRACT Selective molecular recognition is central to chemical sensing yet discriminating structurally similar molecules at complex interfaces remains challenging. Traditional strategies based on tuning size, charge, or binding‐site chemistry often suffer from limited flexibility. Here, we employ dimensionality engineering of cerium‐based metal‐organic frameworks (Ce‐MOFs), comparing 2D and 3D Ce‐MOFs to modulate molecular interactions via spatial conformation matching. Phytic acid (PA), with its distinct 3D inositol hexaphosphate structure, exhibits dimension‐dependent interfacial assembly behavior. In 2D Ce‐MOF, PA acts as a “molecular bridge” inducing interlayer stacking (∼fivefold thickness increase) and leading to strong noncompetitive inhibition (IC 50 = 0.053 mM) of its hydrolase (phosphatase)‐mimetic activity. Conversely, confinement within the large pores (14.42 Å) of 3D Ce‐MOF allows partial pore penetration (PA cross section: 10.46 Å) resulting in weak competitive inhibition (IC 50 = 1.7 mM). Spectroscopy ( 31 P NMR, FTIR) and zeta potential testing confirmed analogous PA‐Ce coordination modes in Ce‐MOFs ruling out chemical disparity as the cause. Density functional theory (DFT) calculations further verified the interlayer bridging in 2D MOF and intrapore confinement in 3D MOF as distinct adsorption modes. This fundamental difference—interlayer stacking versus confined penetration driven by dimensionality engineering creates a unique “dimensional fingerprint” for PA. Leveraging this orthogonal response (noncompetitive vs. competitive inhibition), we demonstrate a sensing strategy for selective PA identification. This work establishes dimensionality engineering as a powerful paradigm for rational interface design and selective recognition based on analyte spatial architecture.