Sustainable Device Based on Reduced Graphene Oxide and Carbon Black 3D Printed for Sensitive Monitoring of Paracetamol

The additive manufacturing technique through fused deposition modeling (FDM), popularly known as 3D printing, has become a powerful tool for the fabrication of electrochemical sensors, as it allows the development of different device models at a low cost. Thus, this work describes the use of a commercial conductive filament composed of carbon black (CB) dispersed on a polylactic acid (PLA) polymer matrix to construct a disposable electrode for monitoring paracetamol (PAR) in pharmaceutical formulations by differential pulse voltammetry (DPV). Additionally, the sensor was modified with reduced graphene oxide (rGO), evidencing the synergistic effect of carbon nanomaterials with anticipation of the oxidation peak, increase of the analytical response, and favoring of the oxidation-reduction process on the electrochemical surface. The sensor was further characterized by microscopic and electrochemical techniques. The optimized method by DPV promoted a wide linear working range (10 to 300 mu mol L-1), excellent detectability (72.5 nmol L-1), and adequate precision (RSD <3.6 %) and accuracy with recovery percentages of 96 and 102 % for doped samples. Furthermore, the sensor is free from interference with other substances in the pharmaceutical formulation matrices. Finally, the reliability of the results was statistically attested by comparison with those obtained by liquid chromatography. So, the proposed method is accurate for the monitoring of paracetamol in pharmaceutical formulations, highlighting the lower reagent consumption and interferences in the analytical process.