A prompt electrochemical monitoring platform for sensitive and selective determination of thiamethoxam using Fe2O3@g-C3N4@MSB composite modified glassy carbon electrode

The current study reported the synthesis of Fe2O3 @g-C3N4 @melamine Schiff base via a simple and effective methodology. The prepared composite was well characterized by diverse characterization techniques X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer, Emmett and Teller (BET), Field emission scanning electron microscopy (FESEM) with energy dispersive spectrometry (EDS) mapping, High-resolution transmission electron microscopy (HRTEM) and UV Visible spectrophotometer, which indicated the formation of desired pure composite material. Further, the prepared Fe2O3 @g-C3N4 @melamine Schiff base modified GCE was applied for the detection of thiamethoxam (TMX), a class of neonicotinoid pesticide. Additionally, the influence of numerous parameters such as the amount of electrocatalyst loaded, pH of the solution, accumulation temperature, and accumulation time was also studied to achieve efficient detection. Furthermore, the cyclic voltammetry (CV) and linear sweep voltammetry (LSV) revealed that the composite acts as an excellent sensor for the electrochemical determination of TMX and attained a very low limit of detection (0.137 µM / 39 ppb) with a broad linear range of 0.01–200.00 µM. Further, to evaluate the stability of the designed sensor; the prepared Fe2O3 @g-C3N4 @melamine Schiff base was also coated on the screen-printed electrode and the electrochemical experiment was performed by it for a period of 30 days. It was depicted that the proposed sensor afforded satisfactory stability, reproducibility as well as repeatability for TMX detection. Moreover, the current work also offers a promising approach for the electrochemical detection of TMX in real samples like potato, rice, and river water.