Disposable and flexible screen-printed-carbon electrode modified with Au/poly-beta-cyclodextrin as electrochemical platform for estriol detection

Abstract

In this work, a screen-printed carbon electrode in polyethylene (SPPE) modified with Au particles and poly-beta-cyclodextrin polymeric film (SPPE/Au/p-beta-CD) was develop as an electrochemical platform to detect estriol (E3) in environmental and biological samples. The stability, reproducibility and sensitivity of the electrode were confirmed via physicochemical and electrochemical characterization. Electrochemical tests demonstrated an increase in the SPPE electroactive area when 70% graphite ink was applied, and transmission electron microscopy revealed an increase in surface complexity compared with that of the unmodified electrode. The electrochemical impedance spectroscopy (EIS) to SPPE/Au/p-beta-CD data indicated a decrease and increase in the Rct (0.096 kΩ cm2) and constant phase element (CPE) (28.34 µF cm−2) values, respectively. The analytical curve was plotted using concentrations ranging from 2.0 to 48.5 µmol/L and the best results were obtained at pH 4.0; a limit of detection (LD) of 1.88 µmol/L was obtained. During a study of interferents, the platform exhibited high selectivity for E3. The SPPE/Au/p-beta-CD exhibited recovery percentages of E3 between 100.32–110.17% in river water, and female urine, saliva, and sweat. The SPPE/Au/p-beta-CD as electrochemical platform proved to be a reproducible, selective, and low-cost sensor for the detection of E3 in different complex matrices. The modification of SPPE with Au and the beta-CD polymer made the electrode more sensitive and the method used is viable for real application.