Determination of Perfluorooctanesulfonic acid in water by polydopamine molecularly imprinted /Gold nanoparticles sensor

This research aimed at developing an electrochemical sensor for the sensitive and selective determination of trace levels of Perfluorooctanesulfonic Acid (PFOS) in environmental water. The sensor (PFOS-MIPPDA/AuNPs/GCE) reported here is based on a glassy carbon electrode electrodeposition with gold nanoparticles (AuNPs) and modified with a molecularly imprinted polymer (MIP), which was prepared through the in situ electropolymerization of dopamine (DA) with PFOS as the template. Then, a new method for PFOS determination was established by differential pulse voltammetry using K3[Fe(CN)6] as the detection probe. The optimal conditions for the preparation and analysis of the sensor were investigated. The surface morphology and electrochemical properties of the sensor were characterized by scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Results showed that the PFOS-MIPPDA/AuNPs/GCE sensor prepared by this method has good recognition performance, the linear range for PFOS detection is 0.01–8.00 µmol/L, and the detection limit is 0.0042 µmol/L. The result is satisfactory when used to analyze real water samples with recovery between 96.9 % and 104.6 %. This method has low cost, sensitive detection, and fast operation and has a potential application prospect for PFOS detection in environmental water samples.