A Sensitive and Selective Electrochemical Sensor Based on an Iron-Based Nanocomposite-Modified Electrode for the Detection of Dopamine in Pork

Here, a highly sensitive and selective electrochemical sensor for dopamine (DA) determination in pork was developed. This sensor was fabricated using iron-based nanocomposites (Fe@(C-S-N)) to modify a glassy carbon electrode (GCE) substrate. The Fe@(C-S-N) nanocomposites were synthesized through a facile low-temperature chemical precipitation approach by adopting ferrous sulfate and melamine as raw materials, with their structural and compositional properties thoroughly investigated using multiple analytical techniques, including X-ray diffraction (XRD), electron microscopy (EM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive spectra (EDS). Cyclic voltammetry (CV), chronocoulometry (CC), and differential pulse voltammetry (DPV) were adopted to investigate the electrochemical performance of the fabricated Fe@(C-S-N)/GCE sensor. Notably, the sensor demonstrated a linear response range from 0.05 to 100 μM with a minimal limit of detection (LOD) of 46 nM. Lastly, the fabrication sensor was used to determine DA in pork samples, showing an acceptable recovery of over 96.89%. Thus, the proposed sensor could offer an effective method for determining DA in pork.