Electroanalytical Determination of Estrone in Seawater Samples Using Functionalized Multiwalled Carbon Nanotubes

Abstract

In this work, a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes functionalized with carboxylic groups (MWCNT−COOH) was used to determine the hormone estrone in seawater samples. Modification of the electrode was optimized using three successive 10‐μL aliquots of the MWCNT−COOH dispersion in ethanol (1 : 5 mL). The cyclic voltammetry results showed an oxidation peak at 0.59 V with characteristics of an irreversible process, pH dependent and controlled by adsorption of species. The results of square‐wave voltammetry showed that the intensities of peak currents for the MWCNT−COOH/GCE were about 2.5 times higher than for GCE. The calibration curve showed a linearity of 0.9981 and a sensitivity of 0.1521 μA/mol L−1. The limits of detection and quantification were 0.117 and 0.392 μmol L−1, respectively. The recovery obtained using seawater samples was 91%, indicating the applicability of the method in marine environments.

Development of a selective graphene quantum dots based electrochemical sensor for the determination of estrone in different water matrices and synthetic urine

“…Furthermore, the slope corroborates the widespread mechanism of the electrochemical oxidation of E1, leading to the formation of quinone through an irreversible reaction. This reaction involves the transfer of two H + and a pair of electrons (Figure 2c) [6,8,25].…”

“…Another source of contamination is sewage, as conventional sewage treatment is often ineffective in removing small organic molecules, allowing estrogens such as E1 to be present even in treated water [6]. Owing to the consequences of short exposure of aquatic organisms to estrogens, even at low concentrations, the urge to monitor these compounds in aquatic systems has been an object of discussion by environmental organizations worldwide.…”

“…For instance, to detect E1 in seawater by chromatography, sample preparation is a critical step because of the high concentrations of ions that cause high ionic resistance, as well as the presence of matrix interferents with their hermetic seal structure. Thus, the analysis of E1 is more expensive and challenging [6].…”

“…The determination of estrone using a simple, fast, and efficient method is of great interest because of the many problems it can cause [3]. In this way, the determination of estrone through electrochemical methods becomes a promising alternative because they are simple operation methods [9,10], which have low limits of detection and quantification, not to mention that this technique reduces the production of potentially harmful substances considerably [6,11].…”

Research developments in carbon materials based sensors for determination of hormones

“…In this perspective, Okina et al [141] described a sensor for EN, based on a glassy carbon electrode incorporated MWNTs, functionalized with carboxylic groups. The reported sensor detects…”