Exploring the potential of β-Cyclodextrin@Ti3C2Tx MXene in electrochemical chiral recognition of tyrosine enantiomers

Abstract

An electrochemical chiral sensor based on β-cyclodextrin@Ti3C2Tx MXene/screen printed carbon electrode (β-CD@MXene/SPCE) was developed for the determination of D- and L-tyrosine enantiomers for the first time. Morphological characterization of the material (β-CD@MXene) was performed using Field Emission-Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM) imaging, while X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) confirmed the crystalline structure and interaction between MXene and β-CD in structural characterization. To evaluate the electrochemical characterization of the modified electrodes, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were applied. To investigate the electrochemical behavior of the tested D- and L-amino acid enantiomers, CV and differential pulse voltammetry (DPV) techniques were conducted. Among the tested chiral species, only D- and L-tyrosine showed distinct voltammetric signals. To investigate the electrochemical behavior of D- and L-tyrosine, CV and DPV techniques were conducted revealing an increase in oxidation peak currents with the increasing tyrosine concentration levels. The voltammetric response of racemic D/L-tyrosine was also examined. For real sample analysis, human serum was used in chronoamperometric measurements (10–100 µM), yielding a linear response. The LOD and LOQ values were 3.15 µM and 9.45 µM, respectively, for D-tyrosine, and 4.68 µM and 14.05 µM, respectively, for L-tyrosine in human serum samples.