3D spongy nanoflower-like Fe2O3–rGO composite for sensitive electrochemical detection of epinephrine

Epinephrine (EP) is a crucial hormone secreted by adrenal, and its secretion and transmission are closely associated with various health conditions. Therefore, developing advanced EP detection methods is of great importance. Herein, an innovative electrochemical sensor has been successfully established based on the Fe 2 O 3 and reduced graphene oxide (Fe 2 O 3 –rGO) nanocomposite. Benefiting from the vast specific surface area of Fe 2 O 3 and the high conductivity of rGO, the Fe 2 O 3 –rGO nanocomposite was synthesized via a solvothermal method. The material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to analyze its phase composition and morphology. The built sensor demonstrated highly sensitive and selective detection performance towards EP. The Fe 2 O 3 –rGO sensor demonstrated outstanding analytical performance for EP detection, achieving a low detection limit (LOD) of 0.18 µM and a wide linear range from 0.2 to 30 µM. This performance is superior to that of most previously reported electrochemical sensors for EP. The selectivity tests confirmed that the sensor showed excellent anti-interference capabilities against EP structural analogs and other potential interfering substances. In real sample assays, the Fe 2 O 3 –rGO sensor was successfully used to determine EP in commercial veterinary drug and spiked human serum samples, fully demonstrating its practical analytical value.