Abstract: In this work, an electrochemical chiral sensor of a nanowire-like chiral metal-organic framework/multiwalled carbon nanotube- chitosan/glassy carbon electrode (D-MOF/MWCNTs-CS/GCE) was proposed for the enantiorecognition of L/D-tryptophan (L/D-Trp). The asymmetrical spatial structure of D-MOF provides the feasibility for the enantiorecognition of Trp enantiomers. Moreover, differential pulse voltammetry (DPV) was carried out to be the detection method and the DPV peak potential difference (ΔE_p) between L-Trp and D-Trp was referred as the index of the enantiorecognition performance. Several parameters, such as mass ratios and drop-coated volume of MWCNTs-CS, drop-coated volume and concentration of D-MOF, pH and detection temperature of D-MOF/MWCNTs-CS/GCE were optimized for the largest ΔE_p value. And the molecular dynamics (MD) simulation was used to elucidate the enantiorecognition mechanism. Furthermore, the proportions of D-Trp (D-Trp%) in Trp mixtures were detected in a good linear relationship with the DPV peak potentials (E_p), and the proposed electrochemical chiral sensor exhibited good reproducibility, stability and enantiorecognition ability. Additionally, the proposed electrochemical chiral sensor (D-MOF/MWCNTs-CS/GCE) has a good application prospect in the fields of biomedicine, clinical diagnosis, chemical production, pharmaceuticals safety and so on.

Key words: Electrochemical chiral sensor, Chiral metal-organic framework, Multiwalled carbon nanotube-chitosan (MWCNTs-CS), D-MOF, Tryptophan (Trp), Potential difference (ΔE_p)