NUOVI SENSORI ELETTROCHIMICI A STAMPO MOLECOLARE PER PERFLUOROOTTANSOLFONATO E SUOI DERIVATI

摘要

The perfluorooctansulfonate (PFOS) is a surfactant used in a variety of industrial products. Due to the characteristics of persistence, bioaccumulation and toxicity (PBT), pollution from PFOS is a problem of global interest. This study describes the manufactures and the characterization of a new sensor for PFOS based on a molecularly imprinted polymer (MIP) prepared by electropolymerization of polyortophenylenediamine (o-PD), on a suitable electrode in the presence of PFOS as molecular mold or templating agent (template). After polymerization, the molecules of templating agent are substantially removed from the polymer matrix by washing with hydroalcoholic solution. Electrochemical methods are used to monitor the electropolymerization process, the removal of the templating agent and the binding, preferably in the presence of ferrocenecarboxylic acid (FcCOOH) as electrochemical probe. The imprinted layer is characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and scanning electron microscopy (SEM). Some factors that influence the performance of the MIP-modified electrode are described and optimized. The electrode, advantageously usable in the concentration range from 0.1 nM to 1.5 μM, with a limit of detection equal to 0.038 nM (S/N=3), has excellent capability of qualitative and quantitative recognition for PFOS.