Preparation and characterization of molecularly imprinted mussel inspired film as antifouling and selective layer for electrochemical detection of sulfamethoxazole

The present work describes the development of a novel simple and cheap electrochemical sensor based on molecularly imprinted polydopamine, for the detection of sulfamethoxazole (SMX) an antibiotic widely used in food industry. A double step procedure is used for sensor fabrication consisting in molecularly imprinted polydopamine (PDA-MIP) electropolymerization on a gold electrode and template removal through a simple washing procedure with diluted acetic acid. SMX detection was then performed amperometrically. A deep investigation of PDA-MIP electropolymerization was performed combining electrochemical, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) characterization and comparing the obtained results with the corresponding non-imprinted polymer (PDA-NIP), evidencing, for the first time, the possibility of secondary reaction that can occur between template molecule and polymer during material synthesis. Antifouling properties of here prepared PDA-MIP film were observed avoiding the use of complex cleaning procedure of electrode surface during the measurements. Under the selected optimum conditions, MIP sensor evidenced a linear range from 0.8 to 170 mu M and a good selectivity in presence of other structurally related molecules such as sulfadimethoxine. The PDA-MIP film was then used for the first time in food analysis to determine SMX in spiked milk samples at two different concentrations (3.4 mu M and 9.8 mu M) obtaining satisfactory recovery results (103 +/- 6% and 99 +/- 8% respectively). (C) 2017 Elsevier B.V. All rights reserved.