Carbon microelectrodes with customized shapes for neurotransmitter detection: A review

Carbon-based electrochemical biosensors as diagnostic platforms for connected decentralized healthcare

“…Direct correlation was reported between the tip length and the number of microelectrodes inserted improve the sensitivity of these microelectrodes, enhance electron transfer rate, and increase conductivity 136 . The performance of these electrodes can be enhanced by carefully selecting the required customized shape and size of carbon nanostructures, e.g., nanotips, cavity nanopipettes, etc., 137 .Nano-sized electrodes can be prepared by nanoprinting method via flame etching, designed electrodes can be inserted in the synapses for studying cell exocytosis 138 .Growing carbon nanospikes on tungsten and niobium metal wires enabled mass production of nano-tip electrodes for sensitive detection of dopamine, serotonin, ascorbic acid, and 3,4-dihydroxyphenylacetic acid (DOPAC). (Figure 13A) shows the SEM images of tungsten and niobium wires with carbon nanospikes (CNSs) modification.…”

“…136 The performance of these electrodes can be enhanced by carefully selecting the required customized shape and size of carbon nanostructures, e.g., nanotips, cavity nanopipettes, etc. 137 Nano-sized electrodes can be prepared by nanoprinting method via flame etching, designed electrodes can be inserted in the synapses for studying cell exocytosis. 138 Growing carbon nanospikes on tungsten and niobium metal wires enabled mass production of nano-tip electrodes for sensitive detection of dopamine, serotonin, ascorbic acid, and 3,4-dihydroxyphenylacetic acid (DOPAC) (Fig.…”

Wireless, Battery-Free Implants for Electrochemical Catecholamine Sensing and Optogenetic Stimulation

“…The progression of technology for monitoring neurological signals has substantially expanded the capabilities and understanding of neuroscience over the past decade. − Despite this, the available technologies for such studies largely require bulky, power intensive benchtop systems with complicated operational procedures that require highly trained staff and constant care of the experimental subjects. Real-time, continuous monitoring of in vivo neurotransmitter dynamics presents a key operational capability that is needed to fully elucidate neural pathways involved in several disease archetypes. , Of particular interest among neurotransmitters are catecholamines, particularly dopamine (DA), due to their role in behavioral factors such as motivation and pleasure, , as well as disease archetypes such as addiction, Alzheimer’s, − and Parkinson’s disease. − The development of technologies to monitor dynamics of these neurotransmitters have largely focused on electrochemical sensing modalities, which are reliant on tethered sensing devices that adversely impact subject behavior and limit experimental paradigms. − Alternative strategies that rely on aptamer-based transistor sensors also face similar issues in addition to challenges associated with signal irreversibility, thus impeding acquisition of real-time transients. , The progression of electrochemical detection platforms supported by small, wireless device form factors seek to address these shortcomings through the elimination of tethered connections, allowing for freely moving subjects and reducing the impact on naturalistic behavior. , These devices, however, remain reliant on bulky, oversized batteries (>2 g), which impede uninterrupted operation, increases subject handling requirements, impose operational burden, and negatively impact subject social behavior . These factors are particularly limiting when correlating behavioral phenotype with biochemical measures of neural activity.…”

Review—Catalytic Electrochemical Biosensors for Dopamine: Design, Performance, and Healthcare Applications

“…Electrochemical methods provide an alternative for rapid in vivo and in vitro detection of dopamine. [24][25][26][27] Dopamine is electrochemically active and can be measured directly using an electrode held at its characteristic potential. Electrochemical methods for on-line in vivo analysis of dopamine with carbon fiber microelectrodes (CFMEs) 26 have been described, and the use of methods such as amperometry, [28][29][30] differential pulse voltammetry (DPV), [31][32][33] fast scan cyclic voltammetry (FSCV), 2,34 cyclic voltammetry (CV), 35 electrochemical impedance spectroscopy (EIS), 36 and square wave voltammetry (SWV) 37 is well established.…”