Portable and Cost-Effective Detection of Perfluorooctanesulfonate in Water Using a Screen-Printed Electrode Modified with Molecularly Imprinted Polymer

The widespread contamination of perfluorooctanesulfonate (PFOS) has raised global concerns due to its adverse effects on human health. Consequently, there is an urgent need for sensitive, reliable, and cost-effective techniques for the in-field detection of PFOS in environmental matrices. Herein, we present a portable electrochemical sensor for PFOS analysis, utilizing a screen-printed electrode (SPE) modified with a molecularly imprinted polymer (MIP). The MIP layer specifically recognizes the electrochemically inactive PFOS, hindering electron transfer between the redox probe and the electrode, thereby providing a sensitive and robust strategy for quantifying PFOS. Under optimized conditions, a detection limit of 9.25 ± 1.39 fM (4.98 × 10^–3 ng/L) was achieved using a portable potentiostat. Notably, interference from common coexisting ions and PFOS analogs was negligible. The practical applicability of the sensor was demonstrated by measuring PFOS in water samples, yielding results comparable to those obtained with the established HPLC–MS/MS method while eliminating the need for complex, time-consuming preconcentration procedures. The MIP-modified SPEs holds significant potential as a highly sensitive, cost-effective, and user-friendly technique for in-field monitoring, large-scale screening, and early warning system for PFOS contamination in water.