Nickel tungstate nanoparticles synthesized via a surfactant-assisted method: an efficient platform for...

Accurate detection of dopamine (DPM) is critical due to its essential role in neurological function and its occurrence across diverse biological and food matrices. In this work, we report a novel cetyltrimethylammonium bromide (CTAB)-assisted synthesis of nickel tungstate nanoparticles (NiWO₄ NPs) for the electrochemical determination of DPM in food samples such as yogurt and raw chicken. The successful formation of NiWO₄ NPs was confirmed through XRD, FTIR, and TEM analyses. Electrochemical characterization revealed that the NiWO₄ NP-modified GCE exhibited a significantly reduced charge transfer resistance (R_ct = 165.25 Ω cm²) compared with the bare GCE, along with an enhanced electrochemically active surface area (0.126 cm²vs. 0.092 cm²) in the [Fe(CN)₆]^3-/4- (5 mM)/KCl (0.1 M) redox system. Amperometric i-t studies demonstrated a broad linear detection range from 0.001 to 719 µM with a very low detection limit of 0.47 nM. Furthermore, the NiWO₄/RDE sensor displayed excellent selectivity, operational stability, reproducibility, and long-term stability. Real-sample analysis confirmed its practical applicability, with DPM recoveries ranging from 95.54 ± 0.01% to 99.2 ± 0.37% in yogurt and chicken samples. This work introduces a CTAB-mediated strategy that enhances the biosensing capability of NiWO₄ nanoparticles through improved electrochemical properties, offering a promising and real-sample-compatible platform for effective dopamine sensing.