Quantificação de Metilparabeno Utilizando Sensor Eletroquímico Baseado Em Óxido de Grafeno Reduzido Decorado com Nanopartículas de Rutênio

Parabensare widely used as conservative in cosmetic formulations, pharmaceutical and food, to prevent microbial and fungal attack. However, recent research had characterized these compounds as hazardous to the human health, since they present characteristics of endocrine disruptors, which can be associated with the length of their alkyl chain[1].Justified by the supposed estrogenic effect of these compounds, studies have been developed using highly sensitive techniques, able to identify parabens at trace levels.In this work, the results of electroanalytical determination of MePa,using reduced graphene oxide (rGO) electrode modified with ruthenium nanoparticles (RuNPs),in cosmetic sample are presented. MePa quantification was performed through an electroanalytical method, where the presence of rGO/RuNPs on glassy carbon electrode (GCE)surface allowed the increase of charge transfer target over oxidation process of target molecule. The characterization of the composite material was carried out by transmission electron microscopy (TEM) where it was observed homogeneously dispersed sphere-like nanoparticles of RuNPs with an average diameter of 3.1 ± 0.5 nm dispersed on the surface of rGO.MePa quantificationwas carried outby differential pulse voltammetry. Linear response range(R = 1.0) from 5.0x10-7to 3.0x10-6mol L-1, with LOD 2.4x10-7mol L-1was obtained using the electroanalytical method. The results were compared statistically with the standard technique of detection of these compounds (HPLC). The concentration values found for both techniques were plotted on a linear regression graph, where the chromatographic results (standard technique) were plotted on the x axis, while on the y axis contained the values obtained by differential pulse voltammetry. Thus, both techniques proved to be equivalent, having the same concentration results, with an intercept value equal to zero and slope equal to 1. In other words, the electrochemical methodology showed to be accurate and this allows discussion of the use of electroanalytical methods asalternative toofficial analysis methods in the pharmaceutical, food and environmental context.