This study aims to develop a promising electrochemical sensor based on polymer film overoxidation following the electrochemical polymerization of p-aminophenol on a bare glassy carbon electrode (GCE) surface for the voltammetric determination of sumatriptan succinate (SUM). Cyclic voltammetry (CV), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and square wave voltammetry (SWV) were employed to characterize the electroanalytical performance and morphology of the modified electrode. The results indicated a significant improvement in electrode sensitivity to SUM after electrochemical polymerization and overoxidation of poly(p-aminophenol). We also investigated the effect of all effective instrumental and experimental parameters on sensor response. Under the optimum conditions (accumulation for 60 s at 0.055 V and pH = 2.0), the electrode SWV response to SUM within the range of 1.0-100.0 μM with a limit of detection (LOD) of 0.294 μM was linear under optimized conditions. We also evaluated the selectivity of the designed sensor to different interfering species, suggesting no significant interference. The designed sensor was also used to determine SUM in pharmaceutical preparations and human serum samples with minimal matrix effects, admissible recoveries (99-106), and satisfactory repeatability (1.2-5.1 %RSD). The proposed sensor exhibited admissible repeatability, reproducibility, and stability.
