ORIGINAL RESEARCH article
Front. Bioeng. Biotechnol.
Sec. Nanobiotechnology
Volume 13 - 2025 | doi: 10.3389/fbioe.2025.1642063
This article is part of the Research TopicCarbon Microelectrodes for Neurochemical SensingView all 4 articles
Advancing Glassy Carbon Microelectrode Arrays for Neurochemical Sensing: Impact of Double Pyrolysis on Structure and Function
Provisionally accepted
- 1Louisiana Tech University, Ruston, United States
- 2University of Pittsburgh, Pittsburgh, United States
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Advancing neural interfaces requires implantable devices capable of long-term electrical and chemical monitoring. "All"-glassy carbon (GC) microelectrode arrays (MEAs), in which both electrodes and interconnects are formed from homogeneous GC layer, offer integrated chemical sensing and electrophysiological recording, while enhancing electrochemical durability by eliminating metal components. To guide the development of high-resolution, double-layer "all"-GC MEAs for higher-density architectures, this study systematically investigates GC as both an interconnect and neurochemical sensing material, with particular focus on the effects of double pyrolysis on structural integrity, interconnect resistance, and microelectrode performance. Sheet resistance was analyzed across films of varying thicknesses, and interconnect geometry was evaluated. Raman spectroscopy and X-ray diffraction characterized graphitization and crystallinity, while fast-scan cyclic voltammetry (FSCV) assessed dopamine and serotonin detection. A 48% reduction in the thickness of once-pyrolyzed GC corresponds to a 63% increase in its sheet resistance. A double pyrolyzed GC trace has about 50% higher sheet resistance than a single-pyrolyzed GC trace of the same thickness. Double pyrolysis caused approximately 20% shrinkage in the GC layer. Compared to Cr/Au/Pt traces, GC interconnects had higher resistance at 1–3 µm widths but approached metal-like performance at 5– 10 µm. Importantly, the second pyrolysis cycle preserved structural integrity and FSCV sensitivity. These analyses advance our understanding of GC's electrical and sensing properties, providing critical insights for optimizing compact multilayer devices in next-generation "all"-GC-MEAs.
Keywords: Glassy Carbon, microelectrode array, Pyrolysis, Sheet resistance, fast scan cyclic voltammetry, Serotonin, Dopamine
Received: 05 Jun 2025; Accepted: 01 Sep 2025.
Copyright: © 2025 Sellen, Siwakoti, Sigdel, Zivanovic and Castagnola. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Elisa Castagnola, University of Pittsburgh, Pittsburgh, United States
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