Chiral liquid crystal-MOF composites for electrochemical recognition of enantiomers

Biological systems rely on the exclusive use of L-configured biomolecules for precise molecular recognition, whereas exposure to D-enantiomers can disrupt immune and metabolic processes, underscoring the need for efficient and controllable chiral sensing strategies. Electrochemical chiral sensors offer attractive advantages in terms of sensitivity, simplicity, and cost, yet current approaches predominantly depend on intrinsically chiral materials, limiting their programmability and adaptability. Here, we report a fundamentally different strategy that exploits chiral liquid crystals as programmable chiral fields to induce enantioselectivity in otherwise achiral porous materials. A chiral liquid crystal template is constructed by combining a non-chiral nematic liquid crystal, 4-pentyl-4′-cyanobiphenyl (5CB), with enantiomeric chiral dopants, which directs the ordered assembly of achiral metal–organic frameworks (MOF) into a hierarchical composite electrode interface. The resulting structure integrates long-range order, tunable porosity, and abundant metal-nitrogen coordination sites, enabling sensitive and quantitative electrochemical discrimination of chiral amino acids. Notably, enantioselectivity can be reversibly switched through mirror-image inversion of the liquid crystal chiral field, while the metal-organic framework primarily amplifies electrochemical signals and facilitates mass transport. Experimental results, combined with density functional theory calculations reveal that chiral discrimination originates from enantiomer-dependent adsorption configurations and binding energies at metal-nitrogen active sites. This work establishes programmable chiral liquid crystal–achiral porous material interfaces as a versatile platform for next-generation electrochemical chiral sensing.