Application of a Screen-Printed Carbon Electrode Modified with Printex 6L and Deep Eutectic Solvent for Detection and Quantification of 17β-estradiol

Abstract

This work proposes the development of a screen-printed electrode (SPE) modified with a mixture of Printex 6L carbon and deep eutectic solvent (DES) (SPE-P6LCDES), used for detection of 17β-estradiol (E2) in mineral water, synthetic urine, and artificial saliva. The characterization of SPE was evaluated by Scanning Electron Microscopy, Fourier Transform Infrared and Electrochemical Impedance Spectroscopy. Electrochemical studies for E2 detection were performed in 0.1 mol L−1 phosphate buffer solution at pH 7.0. The linear range of E2 concentration was 0.00732–0.417 μmol L−1 to unmodified SPE and 0.00090–0.21 μmol L−1 to SPE-P6LCDES, with LOD of 0.177 μmol L−1 and 0.0065 μmol L−1, respectively. The use of DES + Printex 6L carbon as a modifier allowed strong intramolecular interactions between DES and the E2 molecule, increasing the intensity of the current response, since it showed high sensibility, sensitivity and reproducibility. The results obtained to E2 recovery on samples were between 92.15% and 102.10%. The validation study (UV–vis spectroscopy) demonstrated recovery of +99.16% (+1.4%) and +100.16% (+1.9%) to 10 and 60 μmol L−1 E2, respectively.