Cobalt molybdenum oxide nanorod decorated carbon yarn for non-enzymatic electrochemical detection of epinephrine

Abstract

Epinephrine (EP), a critical hormone secreted by the adrenal glands, is a vital clinical biomarker linked to various neurological and cardiovascular disorders, making its accurate monitoring essential for diagnosis and patient management. Herein, we report a nonenzymatic electrochemical sensor for EP detection based on carbon yarn (CY) functionalized with cobalt molybdenum oxide (CMO) nanorods. A liquid/liquid interface-assisted strategy using n-butanol and water was employed to tailor the growth of CMO nanostructures. Importantly, the influence of metal precursor concentration on morphology evolution and electrochemical performance was systematically investigated. Controlled nanorod architectures of CMO were formed at optimized concentrations, whereas higher concentrations yielded irregular flake-like structures with minor impurity phases and reduced activity. The optimized CMO-modified carbon yarn exhibited excellent electrochemical activity for EP detection, demonstrating high selectivity, stability, repeatability, and a low detection limit of 2.14 nM. The sensor's practical applicability was validated using real samples, including EP injection solutions and human serum. Finally, a flexible device was fabricated, delivering promising performance.