Rapid Detection of Perfluorodecanoic Acid and Perfluorooctanesulfonic Acid in Foods Using a Molecularly Imprinted Poly(o-phenylenediamine)/Modified Glassy Carbon Electrode

In the current work, a modified glassy carbon electrode (GCE) with excellent conductivity was prepared by drop-coating carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNTs) on the GCE surface. On this basis, two highly selective molecularly imprinted sensors (MIP@PFDA/modified GCE and MIP@PFOS/modified GCE) were separately obtained by in situ electropolymerization of o-phenylenediamine (o-PD) with perfluorodecanoic acid (PFDA) and perfluorooctanesulfonic acid (PFOS) as templates. Under optimal conditions, sensitive quantification methods in the linearity ranges 0.1-1000 ng/mL (PFDA) and 0.05-900 ng/mL (PFOS) were developed via differential pulse voltammetry using [Fe(CN)₆]^3-/4- as a redox probe. The detection limit values of PFDA and PFOS were as low as 0.041 and 0.015 ng/mL, respectively. Both sensors also presented great stability and selectivity in coexistence with other interferences. Lastly, three food samples were utilized to verify the validity and applicability with recoveries of 89.97%-112.27%, confirming its potential for per- and polyfluoroalkyl substances (PFASs) monitoring in a complex matrix.