Mordant black modified glassy carbon electrode for the determination of methylene blue

A new electrochemically sensitive sensor was developed on the basis of mordant black 11 (MT) for the determination of methylene blue (MB). The sensor was constructed by depositing the modifier on a GCE electrode using the drip-casting method. The electrochemical properties of (MB) are studied by cyclic voltammetry (CV) and square wave voltammetry (SWV). Owing to a synergistic effect, the modified electrode exhibited an obvious electrocatalytic effect on positively charged (MB). The influence of experimental variables (accumulation time, supporting electrolyte, accumulation potential, and pH) was systematically studied and optimized for enhanced performance. Under optimum conditions, a linear voltammetric curve was achieved for methylene blue in phosphate buffer solution (pH 6.0) in the concentration range 10⁻⁴ M to 10⁻⁹ M, with a detection limit of 218 nM and a quantification limit of 727 nM. The modified electrode offers numerous advantages, including easy preparation, low detection limit, high sensitivity, good repeatability and stability, short response time, and an effective detection platform for MB in wastewater.