Cubic cobalt ferrite anchored on graphene sheets for non-enzymatic electrochemical detection of 17α-ethinyl estradiol in environmental and biological samples

Recently, the endocrine interference of endocrine disruptors on the environment and aquatic organisms has been a hot topic. Ethinyl estradiol (EE2) is an estrogen endocrine disruptor and one of the most widely used ingredients in oral contraceptives, resulting in high emissions and environmental pollution . Therefore, it is urgent to construct a non-enzymic, simple and low-cost sensor to detect EE2 in environmental and biological samples. We successfully prepared cobalt ferric oxide with anti-spinel structure and reduced graphene oxide composite (CoFe 2 O 4 /RGO) using hydrothermal synthesis, which decorated on the glass carbon electrode (GCE) to detect EE2. The morphological structure of CoFe 2 O 4 /RGO composites was studied by FESEM, HRTEM, EDX, FT-IR, XRD, and XPS techniques. Additionally, the experimental conditions were optimized and the oxidation mechanism of EE2 was explained theoretically and EE2 was detected by CV, EIS, and SWV, which displayed a fantastic current response of EE2. The electrochemical results illustrated that the prepared sensor has good selectivity , high sensitivity, a wide linear range of 0.05–100 μM, and a lower detection limit of 42 nM. Finally, the practicability of the sensor to detect EE2 in real samples was also studied and obtained a satisfactory recovery.