Graphene-ferrocene functionalized cyclodextrin composite with high electrochemical recognition capability for phenylalanine enantiomers.

Graphene oxide (GO) modified with ferrocene (Fc) was successfully assembled via the π-π interaction (GO-Fc) and had the features of large surface area and high loading. Then, a novel composite was synthesized via β-cyclodextrin (β-CD) functionalized GO-Fc by combining the advantages of GO-Fc and β-CD. An efficient chiral electrochemical sensing interface was constructed by using the rGO-Fc-CD composite as the electrode modification for the recognition of phenylalanine (Phe) enantiomers. The successful synthesis of the composites was confirmed by FTIR, XRD, TGA, SEM, and XPS results. The host-guest inclusion interaction was detected by ultraviolet spectroscopy and DPV. The recognition results demonstrated that the rGO-Fc-CD/GCE showed a higher chiral recognition capability for L-Phe than for D-Phe. The enantioselectivity coefficient (I/I) of the proposed sensor was 2.47. The LOD values of 27 nM and 52 nM (S/N = 3) for L-Phenylalanine and D-Phenylalanine were obtained for this electrochemical sensor. The as-synthesized material was successfully exploited for the recognition of Phe enantiomers, indicating that the developed sensor has wide application prospects.