A novel apigenin modified glassy carbon sensor electrode for the determination of copper ions in soil samples

In this study, electrochemical modification of a glassy carbon (GC) electrode with apigenin was carried out and the modified electrode was used for determination of copper(II) (Cu(II)) in soil samples. The GC was modified through the electrochemical polymerization of apigenin (PolyApi/GC) on the electrode surface in aqueous media. The electrode surface was modified with apigenin in phosphate buffer solution (PBS), pH 7, from 0 mV to +1400 mV potential ranges, using 100 mV s−1 sweep rate and 30 cycles by cyclic voltammetry (CV). The surface characterizations of this sensor electrode were performed by CV, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Britton-Robinson (BR) buffer solution at pH 5 was used for determination of Cu(II) by differential pulse voltammetry (DPV). The detection limit was obtained as lower as 1.0 × 10−11 M. By using this calibration curve, the amount of Cu(II) was determined as 7.34 × 10−7 M in soil samples. The results showed that pH, incubation time and interferences of some cations and anions were significant.