Electrochemical Detection of Perfluorooctane Sulfonate in Water Using a Metal‐Organic Framework‐Modified Electrode

Perfluorooctane sulfonate (PFOS), a widely used per‐ and polyfluoroalkyl substance (PFAS), has raised increasing environmental and health concerns due to its persistence and toxicity. In this study, we developed an electrochemical sensing platform based on a glassy carbon electrode (GCE) modified with UiO‐66 metal‐organic framework (MOF) for PFOS detection in aqueous solutions. The modified electrode (MOF‐GCE) was characterized using cyclic voltammetry with ferricyanide as a probe. In the presence of PFOS, the current response decreased as PFOS was adsorbed into the MOF pores, blocking ferricyanide diffusion and thereby reducing current generation. A calibration curve was constructed by plotting the current change as a function of PFOS concentration. Within the linear dynamic range of 0–1000 nM, as established in this study, quantitative analysis of PFOS can be achieved. Under optimal electrode conditions, a low detection limit of 6.2 nM was achieved for PFOS in aqueous solutions. Additionally, this sensor demonstrated high selectivity for PFOS over other contaminants in water environments. These results highlight the potential of MOF‐GCE as a sensitive and selective electrochemical platform for PFOS monitoring in real water samples, offering advantages including rapid response, user‐friendly operation, and compatibility with portable detection systems in practical applications for environmental analysis.