Nanoporous Gold-Modified Screen-Printed Electrodes for the Simultaneous Determination of Pb²⁺ and Cu²⁺ in Water

In this study, nanoporous gold (NPG) was deposited on a screen-printed carbon electrode (SPCE) by the dynamic hydrogen bubble template (DHBT) method to prepare an electrochemical sensor for the simultaneous determination of Pb²⁺ and Cu²⁺ by square wave anodic stripping voltammetry (SWASV). The electrodeposition potential and electrodeposition time for NPG/SPCE preparation were investigated thoroughly. Scanning electron microscopy (SEM) and energy-dispersive X-ray diffraction (EDX) analysis confirmed successful fabrication of the NPG-modified electrode. Electrochemical characterization exhibits its superior electron transfer ability compared with bare and nanogold-modified electrodes. After a comprehensive optimization, Pb²⁺ and Cu²⁺ were simultaneously determined with linear range of 1-100 μg/L for Pb²⁺ and 10-100 μg/L for Cu²⁺, respectively. The limits of detection were determined to be 0.4 μg/L and 5.4 μg/L for Pb²⁺ and Cu²⁺, respectively. This method offers a broad linear detection range, a low detection limit, and good reliability for heavy metal determination in drinking water. These results suggest that NPG/SPCE holds great promise in environmental and food applications.