Voltammetric determination of 17β-estradiol in human urine and buttermilk samples using a simple copper(II) oxide-modified carbon paste electrode

This paper reports the voltammetric determination of 17β-estradiol in urine and buttermilk samples using a simple detector based on a carbon paste electrode (CPE) modified with copper(II) oxide (CuO). The CuO was obtained by the Pechini method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive (EDS), Fourier transform infrared (FTIR), and Raman spectroscopies. Cyclic voltammetry (CV) and square-wave voltammetry (SWV) demonstrated that the CuO-modified carbon paste electrode (CuO/CPE detector) displayed much higher electrocatalytic activity in the 17β-estradiol oxidation reaction than the CPE without modification, exhibiting a low detection limit of 21.0 nmol L −1 with a wide linear range from 60.0 to 800.0 nmol L −1 ( R = 0.998). Satisfactory results were obtained for the determination of 17β-estradiol in human urine and buttermilk samples. The proposed electrochemical detector offers high repeatability, stability, fast response, low cost, and potential for practical application in the quantification of this hormone. Graphical abstract ᅟ