Figure 7.

DPV results of bare GCE, SiO₂/GCE, ZnO/GCE, and ZnO@SiO₂/GCE electrodes measured in 1.75 × 10⁻⁹ molL⁻¹ Cd²⁺. Data were recorded after drop casting 7 µL of a 1 mg mL⁻¹ ZnO@SiO₂ solution in ethanol, a drying time of 2 h, and an accumulation time of 5 min in 0.1 molL⁻¹ in ABS buffer at pH 5.