Disposable electrochemical sensor based on carbon black and ternary oxide (SiO2/TiO2/Nb2O5) for determination of triclosan in mouthwash and water samples.

A new screen-printed electrode (SPE) modified with carbon black and ternary oxide (SiO₂/TiO₂/Nb₂O₅), denominated SPE/CB/SiTiNb and was developed for the direct detection of triclosan in tap water and mouthwash samples. The morphological characterization and electrochemical behavior of the sensors were performed by scanning electron microscopy, energy dispersive spectroscopy, and cyclic voltammetry. Differential pulse voltammetry was used to evaluate the proposed sensor in Britton–Robinson buffer 0.1 mol L⁻¹ and showed a limit detection of 1.23 nmol L⁻¹ in a linear range from 0.025 to 57.01 µmol L⁻¹. Studies with possible interferents were performed demonstrating a significant selectivity of the sensor to the triclosan oxidation reaction. The sensor was applied in tap water and mouthwash real sample analyses, whose recoveries ranged from 93.4 to 98.8%, demonstrating that the sensor shows promise in the detection of triclosan in different matrices allied to high sensitivity, selectivity, low-cost, portability, disposability, and low sample volume, without pre-treatment, per analysis. [ABSTRACT FROM AUTHOR]