Development of a New Electrochemical Sensor Based on Mag-MIP Selective Toward Amoxicillin in Different Samples

Made available in DSpace on 2021-06-25T11:14:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-19 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fondo Nacional de Desarrollo Científico y Tecnológico Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This work describes an electrochemical sensor for the selective recognition and quantification of amoxicillin and a β-lactam antibiotic in real samples. This sensor consists of a carbon paste electrode (CPE) modified with mag-MIP (magnetic molecularly imprinted polymer), which was prepared by precipitation method via free radical using acrylamide (AAm) as functional monomer, N,N′-methylenebisacrylamide (MBAA) as a crosslinker, and potassium persulfate (KPS) as initiator, to functionalized magnetic nanoparticles. The magnetic non-imprinted polymers (mag-NIP) were prepared using the same experimental procedure without analyte and used for the preparation of a CPE for comparative studies. The morphological, structural, and electrochemical characteristics of the nanostructured material were evaluated using Field emission gun scanning electron microscopy (FEG-SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Vibrating sample magnetometry (VSM), X-ray diffraction (XRD), and voltammetric technique. Electrochemical experiments performed by square wave voltammetry show that the mag-MIP/CPE sensor had a better signal response compared to the non-imprinted polymer-modified electrode (mag-NIP/CPE). The sensor showed a linear range from 2.5 to 57 μmol L−1 of amoxicillin (r2 = 0.9964), with a limit of detection and a limit of quantification of 0.75 and 2.48 μmol L−1, respectively. No significant interference in the electrochemical signal of amoxicillin was observed during the testing experiments in real samples (skimmed milk and river water). The proposed mag-MIP/CPE sensor could be used as a good alternative method to confront other techniques to determine amoxicillin in different samples. Laboratory of Physical Chemistry Research Faculty of Sciences National University of Engineering Analytical Department Chemistry Institute State University of São Paulo (UNESP) National Institute for Alternative Technologies of Detection Toxicological Evaluation Removal of Micropollutants and Radioactives (INCT-DATREM) Analytical Department Chemistry Institute State University of São Paulo (UNESP) FAPESP: 2019/00677-7 CNPq: 301728/2019-4 CNPq: 408050/2018-7 CNPq: 465571/2014-0