Norepinephrine-coated defect-engineered chiral MOF enables synergistic enantioseparation in capillary...

Chiral defect engineering offers a versatile strategy for constructing chiral metal-organic frameworks (CMOFs) with tunable structures and chiral recognition, thereby enhancing enantiomeric resolution. However, the stable immobilization of defect-engineered CMOFs onto the inner surfaces of capillaries-crucial for fabricating efficient chiral separation columns-remains challenging. Here, the capillary wall was functionalized with carboxyl groups by grafting GLYMO-IDA-silane, synthesized from 3-glycidoxypropyltrimethoxysilane (GLYMO) and iminodiacetic acid (IDA). On this basis, defect-engineered chiral MOFs (UiO-66-l-Pro) were in situ grown on the modified surface under HCl modulation. Subsequently, a poly(norepinephrine) (PNE)-based molecularly imprinted polymer (MIP) was coated under mild neutral conditions via Fe²⁺-catalyzed polymerization, thereby markedly improving the stability and enantioselectivity of the stationary phase. The resulting MIP@UiO-66-l-Pro stationary phase achieved a significantly enhanced resolution (4.18) in the enantioseparation of tryptophan and demonstrated reliable performance in the quantitative analysis of real samples. This synergistic integration of chiral defect-engineered MOFs with molecularly imprinted polymers provides a novel and efficient strategy for constructing high-performance chiral stationary phases in CEC.