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Multiplexing neurochemical detection with carbon fiber multielectrode arrays using fast-scan cyclic voltammetry


Carbon fiber microelectrodes (CFMEs) have been extensively used to measure neurotransmitters with fast-scan cyclic voltammetry (FSCV) due to their ability to adsorb cationic monoamine neurotransmitters. Although FSCV, in tandem with CFMEs, provides high temporal and spatial resolution, only single-channel potentiostats and electrodes have been primarily utilized. More recently, the need and use of carbon fiber multielectrode arrays has risen to target multiple brain regions. Previous studies have shown the ability to detect dopamine using multielectrode arrays; however, they are not readily available to the scientific community. In this work, we interfaced a carbon fiber multielectrode array (MEA or multielectrode array), to a commercially available four-channel potentiostat for multiplexing neurochemical measurements. The MEA’s relative performance was compared to single CFMEs where dopamine detection was found to be adsorption controlled to the electrode’s surface. Multiple waveforms were applied to each fiber of the multielectrode array simultaneously to detect different analytes on each electrode of the array. A proof of concept ex vivo experiment showed that the multielectrode array could record redox activity in different areas within the mouse caudate putamen and detect dopamine in a 3-mm2 area. To our knowledge, this is the first use of the multielectrode array paired with a commercially available multichannel potentiostat for multi-waveform application and neurotransmitter co-detection. This novel array may aid in future studies to better understand complex brain heterogeneity, the dynamic neurochemical environment, and how disease states or drugs affect separate brain areas concurrently.

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The authors would like to acknowledge the NSF 1707316 grant along with Dr. Paras Patel and Julianna Richie from the Department of Biomedical Engineering at the University of Michigan for the technical assistance and with providing electrode materials.

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The authors would like to acknowledge the following funding sources: American University Faculty Research Support Grant (AGZ), Faculty Mellon Grant, NASA DC Space Grant, NIH 1R41NS113702–01 (AGZ), SACP Pittcon Starter Grant, NSF I-Corps #1936173 (AGZ), NSF MRI # 1625977 (scanning electron microscopy), and American University Fall 2020 Graduate Student Research Grant (HR).

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Correspondence to Alexander G. Zestos.

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All ex vivo animal experiments were conducted in accordance with IACUC guidelines, protocol #20–04.

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Published in the topical collection Electrochemistry for Neurochemical Analysis with guest editors Ashley E. Ross and Alexander G. Zestos.

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Rafi, H., Zestos, A.G. Multiplexing neurochemical detection with carbon fiber multielectrode arrays using fast-scan cyclic voltammetry. Anal Bioanal Chem 413, 6715–6726 (2021).

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  • FSCV
  • Neurotransmitters
  • Microelectrodes
  • Carbon fiber