Recent trends in carbon-based microelectrodes as electrochemical sensors for neurotransmitter detection: A review

Neurotransmitters are biologically active molecules that are crucial for the regulation of normal physiological functions in the central and peripheral nervous systems. Therefore, accurate detection of neurotransmitters is significant in many applications, such as clinical diagnosis, biological analysis, and pathological research. However, quantitative analysis of neurotransmitters is difficult as they are released dynamically and at very low concentrations (e.g., dopamine is released at concentrations of 0.065–0.326 nM) [64]. In this regard, microelectrodes have attracted considerable attention as electrochemical biosensors owing to their excellent sensitivity, high response rate, and high stability. Among the various electrode materials, carbon has shown high potential owing to its high electrical conductivity and low cost. Moreover, carbon-based microelectrodes can be used in real time in vivo to detect neurotransmitters. This review summarizes the various carbon-based microelectrodes developed as biosensors and discusses their sensitivity and limit of detection with regard to neurotransmitters. The review provides insight into the development of carbon-based microelectrodes as biosensors to detect neurotransmitters and the future prospects and commercialization capabilities of such devices.