A sensitive voltammetric analysis and detection of Alizarin Red S onto a glassy carbon electrode modified by an organosmectite

A low-cost, simple and ultra-sensitive voltammetric sensor for the determination of Alizarin Red S (ARS) in aqueous solution using a glassy carbon electrode modified by drop coating of organosmectite film is reported. Various proportions of dimethyldioctadecylammonium (DODA+) cations have been intercalated by cation exchange in the interlayer of the natural clay. Physico-chemical characterization techniques were used to confirm the effectiveness of the intercalation. Electrochemical characterization techniques have been used to determine the surface charge, the permeability, the charge transfer resistance and the real surface of elaborated electrodes. Differential pulse voltammetry (DPV) was used for the reduction of anthraquinone function of ARS, and under optimized conditions, the calibration curve was plotted in the concentration range from 0.01 ​μM to 0.1 ​μM, revealing a detection limit of 3.8 ​nM. The interfering effect of some ions and compounds was evaluated to highlight the selectivity of elaborated sensor. The designed sensor was applied successfully in real samples. © 2021 The Authors