Highly sensitive determination of perfluorooctanoic acid in food and river samples with an electrochemical platform based on MIP and modified MWCNTs

Abstract

Perfluorooctanoic acid (PFOA), one of the emerging persistent organic pollutants, has received great concern due to high resistance to degradation and potential health risks. Numerous reports have revealed its presence in environment (soil, water, air), multiple foods and human blood with certain levels. In this study, a selective electrochemical molecularly imprinted sensor (MIP/CMC-MWCNTs@GCE) based on a template molecule of PFOA and a functional monomer of methacrylic acid (MAA) was developed via electro-polymerization on the surface of a glassy carbon electrode modified with carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNTs) for PFOA detection. The composite electrode was characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to investigate its microstructure and surface groups. Cyclic voltammetry (CV) results and electrochemical impedance spectroscopy (EIS) also showed its excellent electrochemical performance. After optimizing the experimental conditions by differential pulse voltammetry (DPV), the obtained sensor quantified PFOA in a wide range of 0.1 to 2000 ng mL−1 with a low detection limit (LOD) of 0.1287 ng mL−1. Finally, this rapid sensing method has been successfully applied in chicken, peach, tomato and river samples with a recovery rate of 92.00–113.19 %. These results present that the composite sensor has good selectivity, stability and high sensitivity for PFOA determination, which may be a promising alternative for on-site and real-time monitoring in complex samples.