Microfabrication and Characterization of Concentric Nanodes for Brain Chemical Sensing

Wednesday, 31 May 2017
Grand Ballroom (Hilton New Orleans Riverside)
H. Yin, G. Dutta (Louisiana Tech University), and P. Arumugam (Institute for Micromanufacturing)
Understanding the function of human brain is one of the most scientific challenges of the 21st century. Recent studies show the critical role of neurochemicals in several brain disorders such as Epilepsy, Parkinson’s Disease, Alzheimer’s disease and Schizophrenia. Developing advanced chemical sensor technologies that can detect multiple neurochemicals, neurotoxins and local field potentials with high spatial-temporal resolution is urgently needed to better understand the underlying mechanisms. Current chemical microsensors foul quickly and lack sensitivity in long-term use. They also are bulky and lack multiplexing, multimodal capability. In recent times, there is an enormous interest in the use of band, disc and hemispherical nanoelectrodes for novel electroanalytical applications. Albeit their advantages in terms of enhanced analyte transport, low charging currents and high signal-to-noise ratio, they do not provide a 3D electrode geometry that are more suitable for interrogating cells and tissues and are difficult to fabricate multiple nanoelectrodes onto a single cylindrical probe. In this work, we design, fabricate and characterize a novel ring-shaped nanoelectrode “nanode” for brain chemicals of importance. Gold nanodes are micro fabricated on to silicon micropillars and are characterized using SEM, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The nanode’s general electrochemical behavior will be studied in standard redox species. We report the effect of Atomic Layer Deposition coated passivation layers and their thickness on electrical cross talk. Using multiple concentric nanodes (e.g. Au, Pt and boron-doped nano diamond), improvements in chemical signal amplification from dopamine and lead will be discussed.