Enhanced electrochemical enantiorecognition of tryptophan enantiomers based on synergistic effect of porous β-CD-containing polymers and multiwalled carbon nanotubes

Abstract

Porous β-CD-containing polymers (P-CDPs), the polymerization product of β-CD and tetrafluoroterephthalonitrile, demonstrate the high surface area and permanent porosity, which has been applied in removal of organic micropollutants and sulfides by molecular recognition. In this manuscript, an enhanced electrochemical enantioselective platform for tryptophan (Trp) enantiomers was constructed by layer by layer assembly of multiwalled carbon nanotubes (MWCNTs) and P-CDPs on the surface of GCE. The morphologies and performances of the modified electrodes were fully characterized and determined by high resolution field emission scanning electron microscopy (FESEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). And the operation parameters such as temperature and pH on the performance of electrochemical recognition were optimized. Under the optimal experimental conditions, the peak current ratio (Il-Trp/Id-Trp) could reach 2.60. The linear range for the detection of l-Trp on P-CDP/MWCNT/GCE is 8 × 10-6 M to 2 × 10-3 M and for d-Trp is 8 × 10-6 M to 4 × 10-3 M. In addition, the method could predict the ratio of l- or d-isomers in racemic mixture.