A flexible electrochemical sensor based on AuBi bimetal for detection of Cd ions in packaged drinking water

Heavy metal ion Cd, as a toxic pollutant, can accumulate in human body through the bioaccumulation effect of food chain and poses a threat to human health. Packaged drinking water is one of the main water sources for many people, making it crucial to detect their cadmium ion levels. In this work, an AuBi bimetal film was electrodeposited onto a flexible screen-printed electrode to construct highly sensitive cadmium ion sensors. The prepared sensor could enrich trace cadmium ions in the target electrolyte, followed by sensitive detection of cadmium ions using stripping wave voltammetry. The electrochemical results demonstrated that the developed sensor based on AuBi bimetal exhibited a significant linear response to cadmium ions in the range of 50 μg/L to 800 μg/L, with a low detection limit of 11.68 μg/L (S/N = 3), and it also showed good repeatability. The prepared flexible electrochemical sensor was employed to detect the cadmium ion level in five common types of packaged drinking water available on the market, and the relative standard deviation (RSD) and recovery were within normal ranges, indicating that it could achieve rapid and sensitive detection of cadmium ion level in drinking water and other foodstuffs.