▎ 摘　　要

Palladium@gold nanoparticle modified three-dimensional-reduced graphene oxide (3D-rGO/Pd@Au) was coupled with carboxymethyl-beta-cyclodextrin to form a novel nanocomposite (3D-rGO/Pd@Au/CM-beta-CD). The 3D-rGO/Pd@Au/CM-beta-CD served as a chiral sensing interface for the electrochemical enantiorecognition of tyrosine (Tyr) via a differential pulse voltammetry (DPV) approach. The 3D-rGO/Pd@Au demonstrates good electrical conductivity and efficient catalytic activity as an electrochemical indicator. Simultaneously, the CM-beta-CD displays a supramolecular chiral selectivity to reveal a higher binding affinity to the target l-tyrosine (l-Tyr) than to d-tyrosine (d-Tyr). Under the optimized determining conditions, the oxidation peak current ratio of l-Tyr to d-Tyr (I-l/I-d) was 2.12, meanwhile, the peak currents of the two isomers were linearly proportional to the concentration over the range of 0.8-130 mu M with LODs of 52 nM and 96 nM for l- and d-Tyr (S/N = 3), respectively. This approach exhibits distinguished sensitivity, excellent selectivity and good reproducibility, as well as great stability, which can accurately determine the relative content of l- or d-Tyr enantiomers in a racemic solution.