Rapid recognition and determination of tryptophan by carbon nanotubes and molecularly imprinted polymer-modified glassy carbon electrode

• Published in: Bioelectrochemistry (Amsterdam, Netherlands) Netherlands), 2020-02, Vol.131, p.107393-107393, Article 107393
• Main Authors: Wu, Yiyong, Deng, Peihong, Tian, Yaling, Ding, Ziyu, Li, Guangli, Liu, Jun, Zuberi, Zavuga, He, Quanguo
• Format: Article
• Language: English
• Subjects: Carbon; Carbon - chemistry; Chemical sensors; Chitosan; Electrochemical analysis; Electrochemical Techniques - methods; Electrochemistry; Electrodes; Electron transfer; Electrons; Glassy carbon; Hydrogen bonding; Hydrogen bonds; Imprinted polymers; Infrared spectroscopy; Molecular Imprinting; Molecularly imprinting; Morphology; Multi wall carbon nanotubes; Multi-walled carbon nanotubes; Nanotechnology; Nanotubes; Nanotubes, Carbon - chemistry; Oxidation; Polymers; Reproducibility of Results; Scanning electron microscopy; Selectivity; Spectroscopy, Fourier Transform Infrared; Tryptophan; Tryptophan - analysis; Voltammetric sensor
• ISSN: 1567-5394; 1878-562X
• DOI: 10.1016/j.bioelechem.2019.107393

A tryptophan (Trp) molecularly imprinted electrochemical sensor was fabricated by drop-coating an imprinted chitosan film on the surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (MIP-MWCNTs/GCE). The surface morphology and electrochemical properties of the MIP-MWCNTs/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. The electrochemical performance of the MIP-MWCNTs/GCE with Trp showed that the signal of the oxidation current of Trp obtained with MIP-MWCNTs/GCE was significantly enhanced relative to that of the uncovered GCE, indicating that the modified electrode can accelerate electron transfer and has strong selectivity for Trp. The experimental conditions were optimized in parallel, and under the optimal conditions, the MIP-MWCNTs/GCE showed a good linear relationship between the Trp oxidation peak current and Trp concentrations in the ranges of 2.0 nM–0.2 μM, 0.2 μM–10 μM and 10 μM–100 μM The limit of detection (LOD) was 1.0 nM (S/N = 3), and the modified electrode had good reproducibility and stability. Finally, the MIP-MWCNTs/GCE was successfully applied to the determination of Trp in the human serum samples. [Display omitted] •The application of MIP-MWCNTs/GCE for Trp detection was firstly reported.•The imprinted electrode showed good selective affinity for Trp.•The linear range of 2.0 nM-100 μM and the detection limit of 1.0 nM was obtained.•The sensor with low cost, good repeatability and fast response was easy to make.