Electrochemical Determination of 2,4,6-Trinitrotoluene by Linear Sweep Voltammetry Using a Gold Nanoparticle/Mesoporous Graphitic Carbon Nitride Modified Glassy Carbon Electrode

Abstract

A novel electrochemical sensor for 2,4,6-trinitrotoluene (TNT) was constructed using a glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs)/mesoporous graphitic carbon nitride(mpg-C₃N₄) nanocomposite (hereafter designated by AuNPs/mpg-C₃N₄). A facile method based on ultraviolet excitation was used to produce the AuNPs/mpg-C₃N₄ nanocomposite. The new AuNPs/mpg-C₃N₄ nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy. The AuNPs were evenly distributed on the surface of mpg-C₃N₄. The AuNPs/mpg-C₃N₄ modified GCE sensor shows high sensitivity (viz., 0.32 μA/μM) and a low TNT detection limit (42 ppb) by linear sweep voltammetry (LSV). The enhanced electrochemical performance of AuNPs/mpg-C₃N₄ GCE is attributed to synergistic interactions between AuNPs and mpg-C₃N₄. The AuNPs/mpg-C₃N₄/GCE demonstrated good selectivity, stability, and reproducibility for TNT. The AuNPs/mpg-C₃N₄/GCE show a 100% ± 5% TNT recovery for natural water analysis. The results show the potential in AuNPs/mpg-C₃N₄/GCE sensor applications for the determination of TNT.

Keywords:

• Gold nanoparticles
• mesoporous graphitic carbon nitride
• 2,4,6-trinitrotoluene
• glassy carbon electrode
• linear sweep voltammetry

Acknowledgments

The authors acknowledge the financial support from the National Natural Science Foundation of China (Grant No. 21777164) and Initial Scientific Research Fund of Anhui Jianzhu University (2019QDZ64)