A New Electrochemical Platform Based on a Polyurethane Composite Electrode Modified with Magnetic Nanoparticles Coated with Molecularly Imprinted Polymer for the Determination of Estradiol Valerate in Different Matrices

AUTOR(ES)
FONTE

J. Braz. Chem. Soc.

DATA DE PUBLICAÇÃO

24/10/2019

RESUMO

A polyurethane composite electrode modified with magnetic nanoparticles (mag; Fe3O4) coated with molecularly imprinted polymers (MIPs) was developed for the electrochemical determination of estradiol valerate. Chemical and morphological analyses of the mag-MIP were performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), with the aim of characterizing this new material. The efficiency of adsorption of estradiol valerate by the mag-MIP was tested in binding experiments using an electrochemical method. For this, different electrodes (mag-MIP / graphite-epoxy composite (GEC), mag-non-imprinted polymer (NIP) / GEC, mag / GEC, and GEC) were evaluated by square-wave voltammetry (SWV). After 10 min at open circuit potential, increases in the current signal of 1.9, 2.1, and 3.0 times were obtained, comparing the electrochemical response of the mag-MIP / GEC sensor to the mag-NIP / GEC, mag / GEC, and GEC sensors, respectively. Under optimized conditions, the mag-MIP / GEC showed a linear concentration range for estradiol valerate of 5.0 × 10-7 to 7.5 × 10-4 mol L-1 and a limit of detection of 1.0 × 10-8 mol L-1. The proposed sensor was applied in the analysis of pharmaceutical, human urine, and river water samples. The recovery values determined using high performance liquid chromatography (HPLC)-UV and the electrochemical method were in agreement and were near 100%, demonstrating the reliability of the proposed method.

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