Fabrication and characterization of Co3O4-Fe2O3-chitosan based ternary nanobiocomposite electrode for norepinephrine detection

Purpose Neurological disorders such as Alzheimer’s and Parkinson’s diseases are closely associated with abnormal norepinephrine (NE) activity, highlighting the need for its sensitive and reliable detection. This study aims to develop a cost-effective and efficient electrochemical sensing platform for real-time monitoring of NE in biological and clinical applications. Design/methodology/approach A glassy carbon electrode (GCE) was modified with a Co3O4–Fe2O3–chitosan (CS) nanobiocomposite via a facile co-precipitation method. The nanobiocomposite was structurally and morphologically characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. Electrochemical behavior was investigated through cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. Analytical parameters such as sensitivity, linear range and detection limit were determined, while spike–recovery tests in human serum were performed to validate the practical applicability of the sensor. Findings The fabricated Co3O4–Fe2O3–CS/GCE exhibited a strong linear current–concentration response for NE within the range of 3–25 µM (Ipa [µA] = 0.791C (NE) + 0.437, R2 = 0.99), with a low detection limit of 0.64 µM. The electrode demonstrated excellent sensitivity, stability and reproducibility compared with conventional unmodified electrodes, confirming its superior electrochemical performance. Research limitations/implications This study is limited to laboratory-scale validation, with tests focused on a specific concentration range. Broader trials in complex biological matrices and long-term stability assessments are required to establish clinical translation. Future research should explore scaling up fabrication and integrating the electrode into portable sensing devices. Practical implications The proposed electrode offers a low-cost, highly sensitive and biocompatible platform for NE detection. Its demonstrated performance in real serum samples highlights its potential for use in clinical diagnostics, portable biosensing devices and point-of-care monitoring, making it attractive for commercialization in health-care technologies. Social implications Early and accurate detection of neurotransmitter imbalance can significantly improve the diagnosis and treatment of neurological disorders. This sensor provides an accessible and reliable tool for health-care systems, potentially reducing disease burden, improving patient quality of life and supporting the development of personalized medicine. Originality/value This work introduces a novel ternary nanobiocomposite (Co3O4–Fe2O3–CS) as an effective electrode modifier. By combining the synergistic catalytic effects of metal oxides with the biocompatibility of CS, the developed electrode provides enhanced sensitivity and reliability for NE detection. Its low cost, facile preparation and demonstrated performance in real serum samples make it a promising candidate for next-generation electrochemical biosensors in healthcare diagnostics.