Electrochemical sensing platform for the detection of nitroaromatics using g-C3N4/V2O5 nanocomposites modified glassy carbon electrode

Abstract

Rapid, reliable, cost-effective and trace-level detection of nitroaromatic toxins is becoming increasingly important because of their carcinogenic nature, and their presence in water sources as an environmental contaminant. The present study reports the development of an electrochemical sensing platform based on g-C3N4/V2O5 (VOCN) nanocomposites modified glassy carbon electrode (GCE) for the effective detection of nitroaromatics. The VOCN nanocomposites were synthesized via wet impregnation method, and were characterized by XRD, FT-IR, HRSEM and XPS techniques. The electrochemical behavior of four nitroaromatics (4-NP, DNP, DNT and TNP) were investigated on seven nanomaterials-based sensors using cyclic voltammetry, square wave voltammetry and chronoamperometry techniques. Under optimized conditions, the nitroaromatic compounds exhibited reduction peaks corresponding to the number of nitro-functional groups on an aromatic ring. The electrochemical studies revealed that the composite with 7 wt% V2O5 (VOCN7/GCE) exhibits higher sensitivity for the detection of 4-NP, DNP, DNT and TNP. The VOCN7/GCE recorded the limit of detection (LOD) as low as 0.85 nM, 3.3 nM, 3.4 nM and 11.0 nM in a linear range between 1.0 nM - 100.0 µM, 10.0 nM - 100.0 µM, 10.0 nM - 100.0 µM and 30.0 nM - 100.0 µM for 4-NP, DNP, DNT and TNP, respectively. The fabricated sensor showed high reusability and reproducibility, and could detect the four nitroaromatics in real water samples.