Enzyme-free electrochemical sensor for dopamine and resorcinol detection using ferrite-polyaniline nanocomposite-decorated glassy carbon electrode

A new type of electrochemical sensor, a ferrite-polyaniline nanocomposite to simultaneously detect resorcinol (Res) and dopamine (DA) was developed. Glassy carbon electrode modification involved the integration of Fe₃O₄-PANI. Structural and surface analyses were performed using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Ultraviolet Visible (UV-Vis) Spectroscopy, and Fourier Transformation Infrared (FTIR) techniques. The sensor (GCE@Fe₃O₄-PANI) exhibited a wide linear range under optimal pH conditions (7.0–7.4), (0.002µM–1500 µM) for both DA and Res, with low detection limits of 2.84 nMand 1.403 nM, respectively. Sensitivity was recorded at 1.10 × 10^-4 A µM⁻¹cm⁻² making it suitable for clinical diagnostics and environmental applications. The suitability of the sensor was confirmed by chronoamperometry, differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). This demonstrates the substantial potential of Fe₃O₄-PANI nanocomposite for the simultaneous and selective identification of DA and Res.