Fabrication of a highly sensitive electrochemical sensor based on electropolymerized molecularly imprinted polymer hybrid nanocomposites for the determination of 4-nonylphenol in packaged milk samples

Herein, an imprinted electrochemical sensor based on graphene-Au nanoparticles incorporated with molecularly imprinted polymer (MIP) was fabricated for determination of 4-nonylphenol (4-NP). Grafted MIP electropolymerized on nanoscale multilayer films electrode was achieved using 4-NP as a template and P-aminothiophenol as a functional monomer. The electrochemical properties of the MIP nanoscale multilayer membrances were characterized and measured by cyclic voltammetry and differential pulse voltammetry techniques; using ferrocyanide/ferricyanide-redox marker. Several important parameters were optimized and investigated to improve the performance of the sensor. Under the optimized conditions, the developed sensor showed an ex- cellent linear response over the concentration ranges of 50-500 ng mL(-1) (4-NP) with a detection limit of 0.01 ng mL(-1)(S/N = 3). The developed sensor showed a good selective recognition of 4-NP compared with structural analogue, exhibited a good reproducibility and accuracy with long-term stability. At last, the feasibility of the proposed methodology was successfully applied fordetection of 4-NP in milk and its packaging materials.