CeO₂ Nanocubes as an Electrochemical Sensing Platform for Simultaneous Detection of Dopamine and Acetaminophen

The overlapping redox potentials of analytes and the lack of selectivity present significant challenges for unmodified electrodes in electrochemical sensing. In this work, we have fabricated an electrochemical sensor based on cerium oxide nanocubes (CeO 2 -NCs) coated glassy carbon electrode (CeO 2 -NCs@GCE) for individual and simultaneous detection of dopamine (DA) and acetaminophen (APAP) with high sensitivity and selectivity. The CeO 2 -NCs were synthesized using a one-step hydrothermal method and characterized by Transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy. Cyclic voltammetry and electrochemical impedance spectroscopy were employed for electrochemical characterizations. With improved electrocatalytic redox activity due to enhanced active surface area and reduced interfacial charge transfer resistance, CeO 2 -NCs@GCE shows superior detection efficiency. The detection of DA and APAP was evaluated using differential pulse voltammetry. Low detection limit values of 0.696 μM for DA and 0.341 μM for APAP with a wide linear range of 10–400 μM applicability were achieved. The CeO 2 -NCs@GCE sensor was also used to detect DA in DA injection and APAP in paracetamol tablet samples. The developed sensor demonstrated satisfactory recovery results ranging from 96.5 to 102.8% in pharmaceutical samples, confirming the applicability of the proposed method for simultaneous detection of DA and APAP in real samples.