Carbon nanotubes as electrochemical sensors for neurotransmitters: Synthesis, doping, and applications

Carbon nanotubes (CNTs) have gained widespread attention in recent years as promising materials for electrochemical sensing given their unique electronic, mechanical, and surface properties. Among various applications, CNTs have been utilized in the modification of electrodes for electrochemical sensing of biomolecules, including neurotransmitters. Catecholamines, including dopamine (DA), epinephrine (EPN), norepinephrine (NEPN), and serotonin (SE) constitute key neurotransmitters, which contribute to various physiological processes. Imbalances in catecholamine levels are associated with neurodegenerative diseases, underscoring the need for rapid and accurate determination of these neurotransmitters in biological samples. This review article presents the main synthetic routes for CNTs, along with doping strategies, emphasizing their impact on CNTs’ properties. We summarize the recent progress in the integration of CNTs-modified electrodes for neurotransmitters detection in terms of sensitivity, selectivity, and clinical sample analysis. Furthermore, we discuss ongoing challenges and future perspectives regarding the optimization of CNTs-modified electrodes applied in real-time diagnostic platforms, thus enabling effective monitoring of neurotransmitter levels in complex biological systems.