Electrochemiluminescent enantiorecognition in a defective chiral metal organic framework

초록

An electrochemiluminescent enantioselective recognition platform was constructed by a defective homochiral MOF (Zn2(bdc)(L-lac)(dmf)), referred to as ZnBLD, exhibiting efficient ECL enantiodiscrimination for phenylalanine (Phe) through differences in ECL intensity. The synergistic effect of chiral transfer and defect induction endows it with excellent enantioselective recognition ability. In the system employing Ru(bpy)32+ as the luminophore, this platform efficiently recognizes Phe across a broad concentration range from 10-9 to 10-2 M, achieving a limit of detection (LOD) of 3.3 x 10-6 M. A high ECL intensity ratio (ECLL-Phe/ECLD-Phe) of 2.8 was observed at 10-4 M. The recognition mechanism stems from the synergistic interaction of three factors, including the increased chiral active sites, an enlarged pore size induced by defects, and favorable electrostatic interactions. Specifically, the spatial adaptability of chiral sites provides a specific recognition environment for lPhe enantiomers, enabling preferential binding to target enantiomers through stereoconfigurational matching; the defect structures in MOFs not only increase the number of active recognition sites but also enhance molecular mass transfer efficiency by enlarging pore sizes, strengthening effective contact with l-Phe and thus improving recognition efficiency; meanwhile, electrostatic interactions between l-Phe and ZnBLD further stabilize the binding system, promoting the formation of stable diastereoisomer complexes and synergistically enhancing ECL efficiency. This research develops a novel ECL enantiodiscrimination strategy based on chiral defective MOFs, providing new insights and possibilities for chiral recognition sensing.

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