Sustainable electrocatalysis: overcoming signal convolution of dopamine and paracetamol at a pristine graphene interface.

Simultaneous electrochemical quantification of dopamine and paracetamol is often hindered by overlapping oxidation potentials and severe surface passivation. To address this analytical gap, a completely reagent-free fabrication approach was developed to construct an electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). The reliance on toxic reducing agents was entirely eliminated by utilizing a direct cathodic potential scan. Through this green process, the conductive carbon network was restored, yielding a highly active electrocatalytic interface. Complete baseline separation between the two target analytes was successfully achieved. Under optimized acidic conditions at pH 3.0, a broad linear dynamic range from 0.1 to 20 µM was obtained for both compounds. Furthermore, the limits of detection (LOD) were 0.008 µM for dopamine (DOP) and 0.016 µM for paracetamol (PAR). Excellent target selectivity was demonstrated even when the sensor was challenged with highly concentrated biological interferents such as ascorbic acid and uric acid. Finally, the platform's practical reliability was validated by analysing commercial pharmaceutical formulations, yielding recovery rates of 96.1-104.1%. These findings were statistically equivalent to standard chromatographic measurements, confirming that a highly accurate, eco-friendly tool is provided for routine clinical monitoring.