In this work, an electrochemical sensor was developed using a carbon paste electrode based on an inorganic matrix modified with metal oxides and iron phthalocyanine (CPE-SiO2/Al2O3/TiO2/FePc) for domperidone (DOM) determination. The modified sensor was characterized by Fourier Transform Infrared (FT-IR) spectroscopy and Scanning Electron Microscopy (SEM). The electrochemical behavior of DOM at the CPE-SiO2/Al2O3/TiO2/FePc was evaluated using cyclic voltammetry. The charge transfer coefficient, α, and the charge transfer rate constant, κ, were found to be 0.22 and 8.56 ± 0.24 s-1, respectively, which indicates it is viable kinetically to be used as a sensor. In order to enhance the response of the base sensor the experimental parameters were optimized. Thus, the best responses were obtained using 19.5 mg SiO2/Al2O3/TiO2/FePc, 10.5 mg graphite powder and 8.0 µL of mineral oil. The modified sensor exhibited a linear calibration curve for DOM over the concentration range of 10 to 80 μmol L1 in phosphate buffer solution (PBS), pH 7.0, with a detection limit of 2.56 μmol L-1 and sensibility of 0.270 μA L mol-1. Therefore, the developed sensor was successfully applied for DOM determination in real samples of pharmaceutical formulation with RSD% lower than 5% indicating that this sensor can be used for routine quality control.
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