Niobium-Decorated Multiwalled Carbon Nanotubes for Voltammetric Detection of Paracetamol

This study investigates the synthesis and characterization of a nanostructured sensor based on multiwalled carbon nanotubes (MWCNTs) decorated with niobium oxide (Nb₂O₅) nanoparticles. The MWCNT-Nb₂O₅ composite was synthesized using a chemical method that ensured a homogeneous distribution of Nb₂O₅ on the MWCNT surface. These nanocomposites were used as modifiers of glassy carbon electrodes for the voltammetric detection of paracetamol in aqueous media. The structural and compositional properties of the material were comprehensively characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermal analysis (TGA-DSC/DTG). Electrochemical analyses, including cyclic voltammetry and square wave voltammetry in Britton-Robinson buffer solution, were employed to assess the performance of the GCE/MWCNT/Nb sensor. The sensor exhibited high sensitivity and precision for paracetamol detection, maintaining reliable performance even in the presence of interferents such as epinephrine and tryptophan. With detection and quantification limits of 0.100 and 5.00 × 10^-10 mol L^-1, respectively, and a recovery rate of 103%, the sensor outperformed several existing electrochemical methods. These findings underscore the suitability of the MWCNT/Nb nanocomposite as a robust platform for precise and accurate paracetamol detection.