title: Electrochemical sensor for sulfadimethoxine based on molecularly imprinted polypyrrole: study of imprinting parameters.
abstract: The present work describes the development of a simple and cost-effective electrochemical sensor for sulfadimethoxine (SDM) based on molecularly imprinted overoxidized polypyrrole (PPy). An all electrochemical approach is used for sensor fabrication and application consisting in molecularly imprinted polymer (MIP) galvanostatic deposition on a gold electrode and its overoxidation under different experimental conditions and in SDM amperometric detection. Several parameters influencing the imprinting effect are critically discussed and evaluated. A key role of the electrolyte used in electropolymerization (tetrabuthylammonium perchlorate and lithium perchlorate) has emerged demonstrating its effect on sensing performances of imprinted PPy and, related to this, on its morphology, as highlighted by atomic force microscopy (AFM). The effect of different overoxidation conditions in removing template is evaluated by analyzing MIP films before and after the treatment by X-ray photoelectron spectroscopy (XPS) also evidencing the correlation between MIP chemical structure and its rebinding ability. MIP-template interaction is verified also by Fourier Transform Infrared (FT-IR) spectroscopy. Under the selected optimal conditions, MIP sensor shows a linear range from 0.15 to 3.7 mM SDM, a limit of detection of 70 μM, a highly reproducible response (RSD 4.2%) and a good selectivity in the presence of structurally related molecules. SDM was determined in milk samples spiked at two concentration levels: 0.2 mM and 0.4 mM obtaining a satisfactory recovery of (97±3)% and (96±8)%, respectively.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Università del Salento, via Monteroni, 73100 Lecce, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Turco
authors.affiliation: NanoInnovation Laboratory, Elettra Sincrotrone Trieste S.C.p.A., S.S.14 Km 163.5, 34149 Basovizza, Trieste, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Corvaglia
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Università del Salento, via Monteroni, 73100 Lecce, Italy. Electronic address: elisabetta.mazzotta@unisalento.it.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Mazzotta
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054802:Molecular Imprinting / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013412:Sulfadimethoxine / Q000032:analysis* / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D013412:Sulfadimethoxine
keywords: Electrosynthesis of molecularly imprinted polymer; Molecularly imprinted overoxidized polypyrrole; Sulfadimethoxine amperometric detection