High sensitive on-site cadmium sensor based on AuNPs amalgam modified screen-printed carbon electrodes

A portable analysis system has been successfully developed for on-site heavy metal ion detection in the environment. The disposable Au nanoparticles (AuNPs) amalgam modified screen-printed carbon electrodes (SPCE) are used in this system for the monitoring of Cd²⁺ in real water samples. The response current is linear to Cd²⁺ concentration within the range of 8.4 ppb to 500 ppm, with a low detection limit of 2.6 ppb. Meanwhile, the surfaces of SPCE could be regenerated by potentiostatic anodic stripping voltammetry. The relative standard deviation (RSD) of voltammetric measurements is 8.3% for five successive measurements on the same electrode. These AuNPs amalgam film modified SPCE provide an integrated electrochemical sensor with high sensitivity and selectivity for the determination of Cd²⁺. This analysis system can be broadly applied in on-site environmental monitoring due to its low cost, usability, and feasibility of mass production, especially for heavy metal ion rapid monitoring during the sudden environmental pollution accidents in China.