A stable electrochemical chiral interface based on graphene-chitosan composites for tyrosine enantiomers recognition

The effective synthesis of graphene oxide (GO) modified with chitosan (CS) via covalent bond exhibited the properties of a wide surface area and high chiral selectivity. The successful synthesis of composites was characterized by the FTIR, XPS and electrochemical methods. Then a novel chiral electrochemical sensor based on chitosan covalently binding with the graphene (RGO/CS) was fabricated for discrimination of tyrosine (Tyr) enantiomers. The results showed that the chiral selector CS preferably combined with D-Tyr rather than L-Tyr, which was attributed to the favorability of host–guest interactions between CS and Tyr enantiomers. In comparison, recognition efficiency was significantly improved after CS was grafted onto RGO, which might be attributed to the formation of intermolecular forces between Tyr enantiomers and CS. Furthermore, the structure of CS could play an important role in enantioselective discrimination. The as-synthesized material was successfully exploited for the recognition of Tyrosine enantiomers, indicating that the developed sensor has wide application prospects.