Electrochemical Synthesis of Polypyrrole Composite with Modified Gold Nanoparticles for Electrochemical Detection of Ascorbic Acid, Dopamine and Acetaminophen in Different Pharmaceutical Samples

This study introduces an electrochemical sensor designed for the determination of ascorbic acid (AA), dopamine (DA), and acetaminophen (AC). The sensor was crafted through a single electropolymerization step in a solution containing pyrrole and modified gold nanoparticles. Characterization of the resulting polypyrrole composite was conducted using diverse techniques, including scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–vis spectroscopy, dynamic light scattering, electrochemical impedance spectroscopy, and cyclic voltammetry. Differential pulse voltammetry was employed to record peak currents for the oxidation of the analytes. The sensor exhibits a linear response within the concentration ranges of 20–1000 μM for AA, 0.1–8.0 μM for DA and 4.0–150 μM for AC with detection limits (3σ) of 8.8 μM for AA, 79 nM for DA and 0.9 μM for AC, respectively. The efficacy of the developed sensor was validated through the electrochemical determination of these analytes in human serum, ampoules, and tablets, demonstrating its practical applicability in real samples.