Sensitive and selective electrochemical sensor of diuron against indole-3-acetic acid based on core-shell structured SiO2@Au particles

In the current study, a simple, recoverable, and stable sensor was developed based on SiO2 spheres functionalized with 6-nm Au nanoparticles (SiO2@AuNPs). Fabrication procedures and analytical application of this sensor toward quantitative determination of diuron in the presence of interfering compound indole-3-acetic acid were verified by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) methods. It has been observed that diuron oxidation at the surface of sensor occurred at a potential of about 1.09 V which was 210 mV higher than that of indole-3-acetic acid, confirming that this newly prepared sensor appeared to be a good platform for the selective detection of diuron. Moreover, DPV demonstrated a linear relationship from 0.20 to 55 μmol/L and a detection limit of 51.9 nmol/L for diuron. Finally, this sensor was utilized for the determination of diuron in complex vegetable samples.