Integrated Carbon Nanotube/Fe ₂ O ₃ –ZnO Nanohybrid Electrode for Sensitive and Selective Simultaneous Electrochemical Detection of Paracetamol and

ABSTRACT

The current study develops an electrochemical sensor that employs iron oxide‐zinc oxide (Fe ₂ O ₃ –ZnO) semiconductor metal‐oxide nanoparticles, along with single‐walled carbon nanotubes (CNTs), to simultaneously detect dopamine (DA) and paracetamol (PA). The active nanomaterials CNTs/Fe ₂ O ₃ –ZnO were synthesized via a simple ultrasonication technique. The feasible synthesis of the nanocomposite was confirmed by various characterization approaches, including x‐ray photoelectron spectroscopy (XPS), x‐ray diffraction (XRD), and field emission scanning electron microscopy (FE‐SEM). The kinetics involved in the electro‐oxidation of target biomolecules was readily identified under optimal conditions. The sensor exhibited a linear concentration range of 5.0–124.77 µM for DA and 5.0–315.25 µM for PA using differential pulse voltammetry (DPV), achieving low limits of detection (LODs) of 0.125 µM for DA and 0.517 µM for PA. The sensitivity was estimated as 1.132 µAµM ⁻¹ cm ⁻² and 0.282 µAµM ⁻¹ cm ⁻² for DA and PA, respectively. The developed sensor exhibits excellent selectivity for target biomolecules even in the presence of different interfering foreign organic and inorganic species. Furthermore, the sensor demonstrates excellent stability under the current experimental conditions. Finally, the sensor demonstrated exceptional practical applicability, achieving near‐complete recovery (≈99%–100%) of DA and PA from human serum samples.