Enantioselective recognition of L/D-amino acids in the chiral nanochannels of a metal-organic framework

Chiral metal-organic frameworks (MOF) have received extensive attention from researchers due to their chiral properties and potential applications in chiral-related fields. However, the construction of chiral metal-organic framework remains challenging due to the unpredictability of the synthesis process and the difficulty in keeping chirality during the growth of chiral MOF. Herein, a chiral MOF (D-His-ZIF-8) is reported for the construction of electrochemical sensing interface, which was synthesized via in-situ substitution of 2-methylimidazole on ZIF-8 by D-histidine (D-His). The introduction of Ketjen Black (KB) to the D-His-ZIF-8 sensing interface can improve its conductivity. The electrochemical recognition results show that KB/D-His-ZIF-8 has enantiodiscrimination ability for amino acids in voltammetry experiments. The best recognition efficiency is observed with Trp enantiomers. The recognition mechanism shows that the chiral nanochannel of D-His-ZIF-8 is conducive to the binding of L-amino acid, which will lead to the recognition of chiral molecules of different configurations. This research points to the possibility of developing further chiral recognition protocols based on D-His-ZIF-8, particularly with the suggested improvement in the preparation procedure of chiral MOF.