Au nanoparticle-poly(ionic liquid) nanocomposite electrode for the voltammetric detection of triclosan in lake water and toothpaste samples

Abstract

Triclosan (TCS), a powerful bactericide agent found in personal care products, has been recently recognized as a contaminant of emerging concern, with endocrine disrupting chemical activity, and whose detection in environmental, biological and/or PCP samples is of great concern nowadays. Therefore, this contribution describes indium-doped tin oxide (ITO) substrates modified with Au nanoparticle-poly(ionic liquid) (Au-PIL) nanocomposite films for the voltammetric detection of TCS in lake water and toothpaste samples. The electroanalytical performance evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), shows the modified electrode oxidizes TCS at much higher oxidation currents than bare ITO. At optimized conditions, the analytical method is linear (R2 > 0.99) in the selected working range (10–60 µmol L−1), presents a sensitivity of 57.1 µA cm−2/mol L−1•and a limit of detection of 0.098 µmol L−1 (28.3 µg L−1). TCS determinations are successfully carried out in spiked lake water samples showing that the electrode response is not affected by such a complex matrix. The concentration of TCS found in a commercial brand toothpaste, simultaneously determined by voltammetry and HPLC, is similar (95% confidence level, t-test) between both techniques and comparable to that described in the product package.