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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 μmol 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. [ABSTRACT FROM AUTHOR]

Glyceline, reline, or ethaline deep eutectic solvents and carbon black nanoparticles within a crosslinked chitosan film are investigated as glassy carbon electrode modifiers for the first time. The selected 5 mgmL-1 glyceline modified GCE was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. Simultaneous determination of acetaminophen and diclofenac by differential pulse adsorptive stripping voltammetry (DPAdSV) presented limits of detection of 2.6×10-8 and 5.2× 10-8 molL-1 for acetaminophen and diclofenac, respectively, in pharmaceutical and biological samples. The obtained results were compared with those obtained by HPLC at a confidence level of 95%. [ABSTRACT FROM AUTHOR]

For the construction of the sensor, three different carbon black (CB) materials (VULCAN XC72R, BLACK PEARLS 4750 and CB N220) were explored as modifying nanomaterial. Firstly, the electrochemical activity of the each SPE modified was compared by cyclic voltammetry and electrochemical impedance spectroscopy technique, using [Fe(CN)6]3−/4− as redox couple. After demonstrating that electrodes modified with different types of CB were characterized by improved electrochemical performances when compared with bare electrodes, and among them, electrodes modified with CB BP4750 is characterised by slightly better electrochemical properties, this type of electrode was used for the development of the analytical method. By applying SWV technique in 0.2 mol L−1 phosphate buffer (pH 3.0), the obtained analytical curves for ACP and LVF were found linearly from 4.0 to 80.0 μmol L−1 and from 0.90 to 70.0 μmol L−1 with limit of detection of 2.6 μmol L−1 and 0.42 μmol L−1 for ACP and LVF, respectively. Finally, the quantification of these drugs in river water was evaluated using the new here‐proposed sensor by recovery method in spiked samples, obtaining satisfactory recovery values. The results achieved demonstrated that the developed analytical tool is of great analytical interest being easy to use, cost‐effective, miniaturized, and thus suitable for low cost on site analysis. [ABSTRACT FROM AUTHOR]

In this work, a simple and highly selective voltammetric method was developed for the simultaneous determination of paracetamol (PCT) and codeine (COD) in pharmaceuticals and human body fluids employing a glassy carbon electrode modified with carbon black (CB) and nickel oxide nanoparticles (NiONPs) within a dihexadecylphosphate (DHP) film. Using square-wave voltammetry (SWV), a separation of ca. 550 mV between the oxidation peak potentials of PCT and COD was obtained. The simultaneous determination of PCT and COD presented a linear concentration range from 3.0 to 47.8 µmol L−1 for PCT and from 0.83 to 38.3 µmol L−1 for COD. [ABSTRACT FROM AUTHOR]