Simultaneous voltammetric detection of cadmium(II) and lead(II) in tapwater using a poly(caffeine) modified glassy carbon electrode

In this work, a novel electrochemical sensing platform was developed based on a poly (caffeine) modified glassy carbon electrode [(Poly(CAF)/GCE)] for the simultaneous determination of lead (II) and cadmium (II). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry were used to characterize the sensor. Cadmium (II) and lead (II) were electrochemically determined using linear sweep voltammetry (LSV) and differential pulse anodic stripping voltammetry (DPASV). For the analytical application, the effects of experimental factors were examined, including scan rate, accumulation time, accumulation potential, and pH of supporting electrolyte solutions. Cadmium(II) and lead(II) were accumulated on the surface of poly(CAF)/GCE at a deposition potential of −2.0 V and a deposition time of 220 s in an acetate buffer of pH 4.5. The linear range was found to be 1.0 μg/L to 40 μg/L with a limit of detection of 0.35 μg/L and 0.28 μg/L for Cd(II) and Pb(II), respectively. The proposed method was found to be highly sensitive and showed good repeatability, reproducibility, long-term stability, and selectivity. The proposed method has been successfully applied to the determination of trace levels of Cd(II) and Pb(II) in tap water.