Synergistically improved electrochemical performance by the assembly of nanosized iron manganese oxide catalyst for the detection of Seleno-L-methionine amino acid

Background: Seleno-L-methionine (L-Se-Met) is an organic selenium compound that serves as an essential trace element known for its potent antioxidant properties. It provides selenium in dietary supplements to support thyroid health, immune function, and antioxidant defense. However, an excessive consumption of L-Se-Met can lead to selenium toxicity and detrimental side effects on human health. Therefore, the development of a fast and sensitive method is needed for the monitoring of L- Se-Met. Methods: Herein, a simple and cost-effective electrode based on iron manganese oxide (Fe₂O₃/Mn₃O₄) catalyst, which could be actuated by a electrochemical sensing platform has been designed. Fe₂O₃/Mn₃O₄ were successfully prepared by the hydrothermal technique. The proposed Fe₂O₃/Mn₃O₄ catalyst was used to modify the glassy carbon electrode (GCE), and the modified electrode was deployed to sense L- Se-Met. The electrochemical characteristics of the fabricated sensor were then studied through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Significant findings: The sensor resulted in a oxidation peak current response that covered a broad linear range from 3.92–992.29 ng/L and had a low detection limit (LOD) of 4.59 ng/L, a limit of quantification (LOQ) of 13.92 ng/L and a sensitivity of 0.0031 µA/µM cm² with outstanding performance. The developed sensor determined satisfactory recovery results for detecting L-Se-Met in samples of broccoli, green bean, green gram, mushroom, onion, red gram and human blood serum using the DPV method.