Iron selenide as an efficient electrode material for electrochemical detection of diuron in environmental waters

Abstract Contamination of surface waters by phenylurea herbicides such as diuron (DUN) remains a persistent environmental concern, demanding sensing platforms that operate reliably under realistic conditions. Here, we report a mixed-phase iron selenide (FeSe) electrode composed of FeSe 2 and Fe 3 Se 4 , obtained through a hydrothermal synthesis followed by thermal conversion, for electrochemical detection of diuron. The coexistence of these two iron selenide phases generates a conductive and redox-active interface that promotes rapid electron transport and efficient surface-mediated oxidation of diuron at neutral pH. The modified electrode displays a clear and concentration-dependent electrochemical response toward diuron using cyclic and differential pulse voltammetry, enabling quantitative analysis with a detection limit of 0.32 μM. Interference studies confirm that the sensing response is largely unaffected by common coexisting organic species and metal ions. The feasibility of the proposed sensor was further demonstrated by accurate diuron determination in pond and river water samples, achieving satisfactory recoveries (93–100.3 %) without complicated sample pretreatment. These findings demonstrate that iron selenide offer a robust and environmentally compatible platform for monitoring herbicide residues in natural water systems.