Nanofabrication of Carbon Electrodes for Neurotransmitter Detection

Fast scan cyclic voltammetry (FSCV) with carbon-fiber microelectrodes has been used as a standard method for real-time detection of neurotransmitters in vivo. Although current carbon fiber electrodes can monitor dopamine as well as some other neurotransmitters, nanofabrication enables new approaches to fabricate functionalized carbon electrodes, including growth of carbon nanomaterials, photolithography, and 3D printing. This dissertation aims to utilize nanofabrication approaches to develop carbon micro/nano electrode sensors, study their electrochemical behaviors related to the surface structures, and apply the electrodes for the detection of neurotransmitters.
Chapter 1 covers the fundamental theories and recent advances of electrochemical detection of neurotransmitters, surface properties of carbon materials, and the nanofabrication methods. Chapter 2 and 3 study the relationship between carbon surface structures and their electrochemical behavior. Chapter 2 demonstrates short, dense and defect-rich nanomaterials are preferred for neurotransmitter detection, and Chapter 3 explores the effects of surface geometric structures of carbon electrodes. Chapters 4-6 describe the 3D printing method to fabricate carbon micro/nano- electrodes for neurotransmitter detection. Chapter 4 introduces the fabrication of carbon microelectrodes with different sizes and geometries, with a submicron resolution for small printed features as proof of principle. Chapter 5 describes the fabrication of 3D printed carbon nanoelectrodes, to realize the neurotransmitter measurement in tiny biological systems. Chapter 6 addresses the development of 3D printing methods of how the conditions are optimized. And finally, Chapter 7 covers challenges and future directions using nanofabrication techniques to fabricate electrode sensors as neuro probes.
Overall, my dissertation explores fundamental electrochemical studies on surface structures of carbon electrodes, and demonstrates the 3D printing micro/nano- carbon electrodes for neurotransmitter detection. The fundamental studies indicate what surface properties and geometry should be designed for neurotransmitter detection, and 3D printing realizes the design of carbon electrodes in a precisely controlled manner. The works benefit the rational design of carbon electrode sensors for different applications.