A Facile Electrochemical Chiral Sensor for Tryptophan Enantiomers Based on Multiwalled Carbon Nanotubes/ Hydroxypropyl-Β-Cyclodextrin Functionalized Carboxymethyl Cellulose

Abstract

The development of facile and convenient sensors for the chiral recognition of enantiomer is of great significance for medical and life science. Herein, a sensitive electrochemical sensor for the chiral recognition of tryptophan (Trp) enantiomers was developed based the assembly of cellulose grafted with hydroxypropyl-β-cyclodextrins (CMC-CD), multi-walled carbon nanotubes (MWCNTs) and copper ions on the surface of GCE. The morphologies and electrochemical behaviors of the prepared electrode (GCE/MWCNTs/CMC-CD-Cu) were characterized by Differential pulse voltammetry (DPV), FT-IR, XPS, cyclic voltammetry (CV) and electrochemical impedance (EIS). The oxidation peak current ratio (IL/ID) of DPV could be reached at 2.2 under the optimal experimental conditions. Compared with D-Trp, the higher electrochemical signal of L-Trp was ascribed to the stronger affinity for L-type tryptophan. Additionally, the as-prepared chiral sensor had been successfully utilized to analyze the amount of D-Trp in the racemic mixture.