Research on electrochemical chiral sensors constructed based on the intrinsic chiral characteristics of AuNPs

Abstract

Nanogold particles inherently possess chiral characteristics. As chiral selectors, they can recognize amino acid enantiomers. Ab initio molecular dynamics (AIMD) simulations were employed to explore the interaction mechanism between gold nanoparticles and D/L-phenylalanine. Additionally, the binding energies of gold nanoparticles with D-phenylalanine and L-phenylalanine were calculated respectively. On the basis of the calculation results, gold nanoparticles were combined with graphene oxide/thionine to form a nanocomposite, which was used to modify the surface of a gold electrode for the recognition of D/L-phenylalanine. Scanning Electron Microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis), and circular dichroism (CD) were utilized to characterize and analyze graphene oxide, thionine, gold nanoparticles, and the graphene oxide/thionine/gold nanoparticle composite material. Electrochemical cyclic voltammetry was used in the construction process and performance characterization of this chiral sensor. Under the same experimental conditions, the electrode modified with the graphene oxide/thionine/gold nanoparticle composite exhibits different current response signals for D/L-phenylalanine. The current response of the binding reaction between nano-gold and D-phenylalanine is stronger than that of L-phenylalanine. The experimental results are consistent with the simulation calculation results. This electrochemical chiral recognition method provides a new strategy for the recognition of chiral enantiomers.