Electrochemical nonenzymatic sensor based on cetyltrimethylammonium bromide and chitosan functionalized carbon nanotube modified glassy carbon electrode for the determination of hydroxymethanesulfinate in the presence of sulfite in foods

An Electrochemical nonenzymatic sensor was fabricated based on cetyltrimethylammonium bromide (CTAB), chitosan (Chit) and carbon nanotube (CNT) nanocomposite modified glassy carbon electrode. Scanning electron microscopy morphology showed that CNT well dispersed in Chit, while CTAB micelles assembled on the surface of the CNT. Due to the synergetic effect of the three components, excellent electrocatalytic activity towards the oxidation of hydroxymethanesulfinate (HMS) in the presence of both fixed and varying concentrations of sulfite was achieved. An enhanced peak current and expanded peak-to-peak separation between HMS and sulfite was observed. Differential pulse voltammetry was applied to quantify HMS and the calibration curve was linear in the range of 30-800 µM with a detection limit of 9.6 µM. The method was applied in the determination of HMS in food samples collected from local markets, and the results have no remarkable difference with the reference HPLC method.