Fusiform-like metal-organic framework for enantioselective discrimination of tryptophan enantiomers

Construction of chiral electrochemical sensors for stereoselective recognition is of great significance in medicine and pharmacy. Compared with traditional chiral recognition materials, metal organic frameworks (MOFs) are undoubtedly a new type of materials for chiral recognition. Here, we report a novel MOFs structure (Phe-Cu-PTA) that formed by the metal ion Cu 2+ and organic ligands [1.10-Pheanthroline (Phe), Terephthalic acid (PTA)], which was used to distinguish L-tryptophan and D-tryptophan (L/D-Trp) enantiomers. Differential pulse voltammetry (DPV) test results showed the ability of the Phe-Cu-PTA to recognize the Trp-enantiomers. Owing to the different steric configuration of the L/D-Trp-enantiomers, host (MOFs)-guest (Trp-isomers) interactions are different for L/D-Trp, the peak current values of L-Trp-and D-Trp-are obviously different, thereby effectively distinguishing the Trp-isomers. The results demonstrated that the developed MOFs (Phe-Cu-PTA) showed significantly higher binding force toward D-Trp-than L-Trp. Therefore, the proposed electrochemical chiral interface can be considered as a potential platform for enantiomeric recognition of chiral compounds.