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

Rosario López; Sabir Khan; Ademar Wong; María Del Pilar Taboada Sotomayor; Gino Picasso

doi:10.3389/fchem.2021.615602

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

Front Chem. 2021 Mar 19:9:615602. doi: 10.3389/fchem.2021.615602. eCollection 2021.

Authors

Rosario López¹, Sabir Khan^{1

2}, Ademar Wong^{2

3}, María Del Pilar Taboada Sotomayor^{2

3}, Gino Picasso¹

Affiliations

¹ Laboratory of Physical Chemistry Research, Faculty of Sciences, National University of Engineering, Lima, Peru.
² Analytical Department, Chemistry Institute, State University of São Paulo (UNESP), Araraquara, Brazil.
³ National Institute for Alternative Technologies of Detection, Toxicological Evaluation & Removal of Micropollutants and Radioactives (INCT-DATREM), Araraquara, Brazil.

Abstract

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 (r ² = 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.

Keywords: amoxicillin; carbon paste electrode; electrochemical sensor; mag-MIP; selective adsorption.