Electrochemical sensor for detection of uric acid in the presence of ascorbic acid and dopamine using the poly(DPA)/SiO2@Fe3O4 modified carbon paste electrode

A nanocomposite of SiO2@Fe3O4 were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive Xray spectroscopy. The poly(dipicolinic acid)/SiO2@Fe3O4 based electrochemical based sensor was fabricated by the electropolymerization of dipicolinic acid (DPA) on the surface of SiO2@Fe3O4 nanocomposite immobilizing the carbon paste electrode (CPE). The developed electrochemical sensor was abbreviated as poly(DPA)SiO2@Fe3O4/CPE. This electrochemical sensor shows an excellent electrochemical activity towards the detection of uric acid. Under the optimized experimental conditions the linear dynamic range (LDR) for the sensing of uric acid was calculated to be 1.2 to 1.8 mu M with a good limit of detection (LOD) and limit of quantification (LOQ) of 0.4 mu M and 1.2 mu M, respectively. The poly(DPA)SiO2@Fe3O4/CPE has also shown the significant sensitivity and selectivity towards the sensing of uric acid in the presence of ascorbic acid and dopamine without any interference. The developed sensor was also successfully applied for the determination of uric acid in real sample analysis.