Square wave voltammetric determination of uric acid and diclofenac on multi-walled carbon nanotubes decorated with magnetic core-shell Fe3O4@SiO2 nanoparticles as an enhanced sensing interface

Multi-walled carbon nanotubes (MWCNTs) decorated with magnetic core-shell Fe3O4@SiO2 nanoparticles were used to fabricate a modified carbon paste electrode (Fe3O4@SiO2/MWCNTs-CPE). The Fe3O4@SiO2/MWCNTs-CPE was investigated for the simultaneous determination of uric acid (UA) and diclofenac (DIC) in phosphate buffer solution (PBS, pH 6.0) using square wave voltammetry (SWV). The synthesized nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) along with energy dispersive X-Ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR). Under optimal conditions, the anodic peak current of square wave voltammetry is proportional to the concentration of the UA and DIC in the range of 0.5 to 100 mu mol L-1. The corresponding detection limits are 0.05 mu mol L-1 for UA and 0.04 mu mol L-1 for DIC (S/N = 3). The Fe3O4@SiO2/MWCNTs-CPE exhibits good storage stability and reproducibility for practical application. It could be applied to simultaneous determination of UA and DIC for the samples with good anti-interference ability.