Fabrication of Ni–Fe2O3 magnetic nanorods and application to the detection of uric acid

Abstract

Doping of Ni into Fe₂O₃ lattices has been achieved by co-precipitation followed by thermal decomposition method. The structural, morphological, and magnetic properties of the fabricated samples were investigated by X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared (FT-IR) spectroscopy, UV-visible absorption (UV-vis) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results reveal that the Ni is well doped within the lattices of Fe₂O₃. The Ni dopant suppresses the formation of more stable α-Fe₂O₃ at higher calcination temperature. Further, the Ni-doped Fe₂O₃ nanoparticles were used to fabricate an electrochemical sensor (Ni–Fe₂O₃/GCE) for the detection of uric acid (UA) in biological conditions by cyclic voltammetry (CV) and chronoamperometry (CA). It was found that 5%Ni–Fe₂O₃/GCE exhibits best response towards UA with less positive potential and larger current response. Furthermore, the sensor gives good linear current response in the concentration range of 6.6 to 112.4 μM with the higher sensitivity of 0.849 μA (μM cm²)⁻¹. Such fabricated sensors are appropriate for newly emerging non-enzymatic electrochemical nanobiosensors.