Figure 9.

Differential pulse voltammograms of ZnO@SiO₂/GCE with different Cd²⁺ concentrations in the presence of potential interfering ions (a) Mn²⁺, (b) Ni²⁺, (c) Pb²⁺, (d) Fe²⁺, and (e) Co²⁺). (f) Histogram of the maximum current peaks for Cd²⁺ at 10⁻⁹ molL⁻¹ in the presence of the different M²⁺ ions (10⁻⁵ molL⁻¹). The electrodes were prepared by drop casting 7 µL of a 1 mg mL⁻¹ ZnO@SiO₂ solution in ethanol, with a drying time of 2 h, and the measurements were taken with 5 min of accumulation time in 0.1 mol L⁻¹ ABS buffer at pH 5.