Conductive polyaniline-graphene oxide sorbent for electrochemically assisted solid-phase extraction of lead ions in aqueous food samples

This work describes an electrochemical-assisted desorption method that has been developed for solid-phase extraction of metal ions (Pb²⁺), based on a well-ordered conducting sorbent: an array-like polyaniline nanofiber synthesized on the surface of graphene oxide (PANI-GO). Combining the advantages of the allowable mechanical deformation of GO with the reduced ionic-diffusion path of vertical PANI nanofibers, this method's synergistic effect lends the prepared sorbent an enhanced stability and high analyte-desorption effectiveness. In terms of the adsorption and electrochemical-assisted desorption behavior of PANI-GO, the paper reports that the adsorption/desorption process is accompanied by the changes of the as-prepared sorbent in cyclic voltammetry, and that the prepared PANI-GO exhibits good anti-interference properties across various interference ions. Given optimal pH values, the limit of detection of the proposed method is 0.04 μg L⁻¹; the repeatability relative standard deviation (RSD) and reproducibility RSD are 1.97% and 2.51%, respectively; and the method shows good recovery capability in the case of real beverage samples spiked with Pb²⁺.