Electrochemical Detection of Methylene Blue Using Ore-Extracted Nb ₂ O ₅ Nanoparticles Modified Carbon Paste Electrode

This study is about the easy and efficient determination of methylene blue (MB), a toxic and carcinogenic cationic dye in wastewater, with Nb 2 O 5 modified carbon paste electrode (NMCPE) using cyclic voltammetry. Firstly, high purity Nb 2 O 5 particles were extracted from the raw ore after a number of procedures. NMCPE was fabricated in phosphate buffer solution (PBS) of pH 6.8 for MB analysis. A maximum current response of 50 μA was recorded during the electro-oxidation of MB using 8 mg NMCPE. The effects of scan rate, pH, and MB concentration were investigated on the anodic current response using cyclic voltammetry. The calculated active surface area for bare and NMCPE is found to be 0.04768 and 0.3311 cm 2 respectively. The limit of detection (LOD) and limit of quantification (LOQ) of the NMCPE were determined to be 0.093 μM and 0.311 μM respectively. The effect of potential interfering species was evaluated like metal ions, dyes, and bioactive molecules and found that, these interferents do not affect the Ipa of MB and the percentage deviation of MB’s Ipa is ±5%. This confirms that, the fabricated NMCPE depicted an extra ordinary selectivity and stability at the same time. This study reports, for the first time, the use of ore-extracted Nb 2 O 5 nanoparticles as a carbon paste electrode modifier for methylene blue detection, offering a cost-effective and sustainable approach.