Analysis of Sumoxen drug via electrochemically reduced graphene oxide sensor: Experimental investigation and molecular docking insights into sensor-analyte interactions

This study presents the electrochemical determination of the anti-migraine pharmaceutical formulation; Sumoxen® (sumatriptan/naproxen) using an electrochemically reduced graphene oxide-modified glassy carbon electrode (erGO/GCE) sensor, with molecular docking employed to elucidate the underlying sensing mechanism. Cyclic voltammetry, differential pulse voltammetry and chronoamperometric techniques were used to assess the performance of fabricated erGO/GCE electrochemical sensor in acetate buffer system (AcBS; pH 5.0) and phosphate buffer system (PBS; pH 6.8). For analytical validation of the fabricated sensor, the limit of detection (LOD), limit of quantification (LOQ), sensitivity, and linear dynamic range were evaluated in the selected buffer systems. At pH 5.0, the sensor exhibited LOD of 1.22 μM, LOQ of 4.07 μM, and an excellent sensitivity of 0.022 μA μM⁻¹ cm⁻². Correspondingly, for naproxen (NPX), the LOD, LOQ and sensitivity were found as 1.881 μM, 6.271 μM and 0.0257 μA μM⁻¹ cm⁻², respectively. At pH 6.8, only NPX produced a measurable electrochemical response, yielding an excellent LOD and LOQ of 23.57 nM and 78.57 nM respectively, and sensitivity of 0.0346 μA μM⁻¹ cm⁻². Kinetic studies have also been done using Tafel analysis and Laviron equation. The standard rate constant (k°) was found to be 1.02 × 10 –4 s -1 . The docking conformation was carried out by calculating binding affinities of erGO model and analytes SUM/NPX and were found as -8.676 kcal/mol and -10.08 kcal/mol respectively, which verified the strong and stable bond interaction between analyte and erGO nanomaterial. The electrochemical method was also assessed for greenness using Analytical Eco-Scale (AES = 97), Analytical Greenness Metric (AGREE = 0.74), and complex Green Analytical Procedure Index (complexGAPI), yielding excellent compliance with green chemistry principles. The relatively low RSD values obtained for repeatability (2.25%) and reproducibility (3.98%), together with the prolonged stability, demonstrate that the proposed erGO/GCE sensor provides a consistent and reasonably stable electrochemical response towards Sumoxen.