Alexander Zestos, Assistant Professor of Chemistry, American University
Multiplexing Neurochemical Detection Using Multielectrode Arrays and Fast Scan Cyclic Voltammetry
Fri, 4 February, 2022
2:00pm
Dr. Alexander Zestos, Assistant Professor of Chemistry, American University
The Department of Chemistry Presents, via online and in-person Zoom Presentation: Dr. Alexander Zestos, Assistant Professor of Chemistry, American University
The brain is by far the most heterogeneous organ, and it is critically important to monitor various brain regions simultaneously in order to understand complex pharmacological, drug, and behavioral states. High temporal resolution neurochemical measurements must be made to study the phasic firing of neurons in several brain regions concurrently. Fast scan cyclic voltammetry (FSCV) and carbon-fiber microelectrodes (CFMEs) have been utilized used to detect several important neurochemicals in vivo. This work will also discuss the development of carbon fiber multielectrode arrays (MEAs) for neurotransmitter detection with FSCV in multiple brain regions simultaneously. Parylene and silicon insulated carbon fiber microelectrode arrays measured neurochemicals in multiple brain regions simultaneously when coupled with multichannel potentiostats. Moreover, we have utilized techniques such as plasma enhanced chemical vapor deposition (PECVD) to deposit conductive carbon nanospikes onto the surface of existing metal multielectrode arrays to give them dual functionality as neurotransmitter sensors with FSCV in addition to being used primarily for electrical stimulation and recording. Other assays have shown the utility of electrodepositing carbon nanotubes and polymers such as PEDOT to coat metal arrays with carbon to give them dual sensing capabilities. Carbon multielectrode arrays performed comparably to single channel CFMEs. We were able to apply four different waveforms to four different electrodes simultaneously. Furthermore, we also measured neurotransmitter release in brains slices using the four-channel carbon fiber array. Making multiplexed measurements of multiple brain regions simultaneously will help understand complex brain heterogeneity.
BIO
Dr. Alexander G. Zestos is a bioanalytical chemist who uses electrochemical and chromatographic techniques for neurotransmitter analysis. He received his B.S./M.S. in Chemistry at the College of William and Mary in Williamsburg, VA. He obtained a Ph. D in Chemistry at the University of Virginia in Charlottesville, VA mentored by Dr. Jill Venton. He was also a postdoctoral research fellow at the University of Michigan from 2014-2017 where he was mentored by Prof. Robert T. Kennedy. Since 2017, he has been an Assistant Professor of Chemistry at American University.
Prof. Zestos has published over 30 papers in prestigious journals such with his research being highlighted in several media platforms. He was named as an Emerging Investigator by the Royal Society of Chemistry for one of his latest publications. He serves as the Faculty Editor of the Catalyst, a student run science publication at American University. He leads an interdisciplinary bioanalytical chemistry group that uses several electrochemical and chromatographic assays to improve neurotransmitter analysis. He serves as a reviewer for the Center for the Scientific Review at the NIH, a referee for several journals, and is new editor of The Chemist through the American Institute of Chemists.