Modified Glassy Carbon Electrode with Mesoporous Silica-Metformin/Multi-Walled Carbon Nanotubes as a Biosensor for Ethinylestradiol Detection

The aim of this study was related to the determination of ethinylestradiol (EE) via electrochemical methods. Since the EE determination has approximately been impossible at low concentrations, the glassy carbon electrode (GCE) was modified with a mixture of metformin (MET), mesoporous silica (SBA-۱۵), and multi-walled carbon nanotubes (MWCNT). Due to the high existence of the NH۲ functional group in MET, this material can act as a modifier by creating a chemical bond by adsorption in SBA nanoparticles, and it subsequently can measure EE. Experimental investigations have shown that the modified electrode has had a repeatable response toward EE evaluation in real samples. Moreover, the physicochemical properties of the manufactured electrode were investigated via FT-IR, field-emission scanning electron microscopy (FESEM), and transmission electron microscope (TEM). Also, the electrochemical characteristics were studied through cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The related result has indicated a considerable increment in current intensity. At optimal conditions, the modified electrode demonstrated linear voltammetric responses in the ranges of ۰.۰۰۵-۲۰۰ µM and a low detection limit of ۱.۶۸×۱۰-۹ M for EE estimation.