Nanocomposite-Based Electrochemical Sensors for Neurotransmitters Detection in Neurodegenerative Diseases

Neurotransmitters (NTs) are crucial regulatory molecules responsible for maintaining the neurophysiological functioning of the brain. Dysregulated levels of certain NTs, such as dopamine, serotonin, norepinephrine, epinephrine, glutamate, and gamma-aminobutyric acid, are often correlated with the pathogenesis of neurodegenerative diseases that involve the progressive and selective loss of structure or function of neuronal systems. Therefore, the identification and validation of relevant biomarkers are essential to diagnose these diseases much earlier. However, the quantitative analysis of NTs is challenging because of their dynamic release and presence of low concentrations. Accordingly, nanocomposite (NC)-based electrochemical sensors have been studied extensively and are gaining tremendous interest due to their high sensitivity, response rate, stability, portability, ease of use in point-of-care diagnostics, amenability to microprocessing, and low cost. In this review, we first briefly discuss the potential biomarkers of neurodegenerative diseases, NC-based electrochemical sensors and their advantages and disadvantages, and the properties of the NCs, which further increase the sensor performance. Finally, we summarized the future perspectives of NC-based electrochemical sensors in the clinical set-up for NTs detection to identify research gaps.