Selective Electrochemical Detection of Dopamine by Using CNF/WO₃/GCE among Uric Acid and Ascorbic Acid Interference

Modern dietary trends in contemporary society can alter biomolecule levels within the human body, posing challenges for electrochemical sensing. Herein, we present a novel electrochemical sensor featuring tungsten trioxide (WO 3 ) nanoparticles on carbon nanofibers (CNFs), forming a composite with outstanding electrochemical properties. The structural integrity and uniformity were confirmed through XRD, SEM, EDX, and TEM analyses. CNF/WO 3 composite possesses a large electroactive area and exhibits enhanced electrochemical performance in detecting Dopamine (DA). Under ideal conditions, the sensor demonstrated remarkable electrocatalytic activity in a 0.1 M PBS at pH 7.0, with a linear range of 0.01–10.0 µM for individual DA detection with a detection limit (LOD) of 0.019 µM and a limit of quantification (LOQ) of 0.0627 µM. For simultaneous detection of DA in the presence of uric acid (UA) and ascorbic acid (AA), the linear ranges were 0.1–2.5 µM (DA), 0.5–10 µM (UA), and 5–50 µM (AA) with the detection limits of 0.25 µM, 0.77 µM, and 4.64 µM, respectively. The sensor exhibits higher selectivity, sensitivity, reproducibility, and stability and its practical utility was tested in biological and pharmaceutical samples, yielding satisfactory outcomes.