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• Gold nanoparticles functionalized with a novel poly(ionic liquid). • The poly(ionic liquid) replaces citrate ions and provides for better colloidal stability of the gold nanoparticles. • Gold nanoparticles-poly(ionic liquid) layer-by-layer assembled nanocomposite enhances the electrocatalytic activity of ITO electrode towards triclosan electro oxidation. • Triclosan is detected at very low concentrations at both tooth paste and lake water samples. • The voltammetric method based on gold nanoparticles-poly(ionic liquid) nanocomposite electrode is insensitive to the matrix effect. 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. [ABSTRACT FROM AUTHOR]

The present work addresses the use of Raman spectroscopy and multivariate curve resolution–alternating least squares (MCR-ALS) for the evaluation of the reaction conversion in copolymerization of aluminum (III) methacrylate and vinyl monomers (vinyl acetate, ethyl acrylate and methyl methacrylate). For the synthesis of these materials, pseudo-dispersion copolymerizations were carried out in a reaction medium containing 17 wt.% of aluminum (III) methacrylate [Al(III)MA] and 83 wt.% of vinyl monomers, such as vinyl acetate (VAc), ethyl acrylate (EA) and methyl methacrylate (MMA). Raman spectra were acquired at different reaction times for each monomer used. We used multivariate curve resolution (MCR-ALS) in order to evaluate the reaction conversion and the concentration profiles. The concentration profile of VAc/Al(III)MA reaction shows that the polymerization occurs slowly, in which the conversion stabilizes after 15 h of reaction. The concentration profile of EA/Al(III)MA copolymerization shows that high conversions are achieved in a short reaction time. However, as the reaction proceeds (between 4 and 12 h), it is possible to observe a decrease of the reaction rate, which is an indication that the modified monomer is polymerizing. The concentration profile of MMA/Al(III)MA copolymerization shows a high conversion in the first 2 h of reaction, indicating a possible low incorporation of the modified metal monomer into the growing copolymer chains, due to the differences of reactivity between the monomer species. The use of Raman spectroscopy coupled with MCR-ALS allowed for the evaluation of the conversion rate of three different organic–inorganic copolymers, although it is difficult to determine the conversion of hybrid polymers, the use of chemometric methods and Raman spectroscopy allowed us to compare the conversion rate between the studied copolymers. [ABSTRACT FROM AUTHOR]