Construction of an electrochemical chiral interface by the self-assembly of chiral calix[4]arene and cetyltrimethylammonium bromide for recognition of tryptophan isomers

Abstract

Molecular self-assembly offers an effective route for the rational design of chiral sensing devices. Here, cetyltrimethylammonium bromide (CTAB) was linked with the chiral calix[4]arene (CCA) via ion–dipole interactions and then an electrochemical chiral interface was constructed from the resulting self-assembled CCA-CTAB. Highly efficient recognition of tryptophan (Trp) isomers (Il-Trp/Id-Trp = 18.96) was achieved with the CCA-CTAB self-assembled interface. Possible mechanisms were proposed, based on density functional theory (DFT) and wettability measurements. Finally, the resulting electrochemical chiral interface was used to analyze the precise levels of l- and d-Trp in a racemic mixture of Trp isomers.