Design and Electrochemical Chiral Sensing of the Robust Sandwich Chiral Composite d-His-ZIF-8@Au@ZIF-8

In the pursuit of chiral materials with significant chiral recognition effects and stability, various strategies have been explored, among which the integration of metal nanoparticles and chiral metal-organic frameworks (CMOFs) is highly promising. However, metal nanoparticles (MNPs)/CMOFs show high chiral properties but inferior stabilities due to the MNPs being easily detached from the outside layer under certain conditions. Sandwich MOFs@MNPs@CMOF chiral materials can overcome this dilemma because the sandwich structure can maximize the regulation of the chiral interface activity, while the controlled outer layer can stop the MNPs from falling off in the procedure of chiral recognition. Here, a novel sandwich chiral material (d-His-ZIF-8@Au@ZIF-8) was synthesized by a ligand-assisted strategy with a well-defined sandwich morphology and chiral recognition capabilities. The electrochemical chiral recognition showed that d-His-ZIF-8@Au@ZIF-8 was the most efficient for the enantiomer of phenylalanine (Phe). This experiment presents a novel perspective for the fabrication of a chiral electrochemical sensing platform based on a solid sandwich chiral nanocomposite.