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

• The combination of metallic copper ion and two organic monomers forms a new type of MOFs material. • The DPV value of new MOFs is higher than that of organic monomers. • Phen-Cu-PTA has a strong ability to recognize tryptophan, and the current ratio of l-type to d-type is 2.3. • The structure of MOFs provides us with new ideas to prepare chiral selectors, and CMOF is a trend. 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. We have reported a novel MOFs for the construction of electrochemical sensing interface. Metal ions Cu 2+ and organic ligands [1.10-phenanthroline (Phen), terephthalic acid (PTA)] are used to identify tryptophan (Trp) enantiomers. The electrochemical recognition results show that the novel MOFs has good recognition effect for tryptophan enantiomers.