AUTHOR=Pepłowski Andrzej , Rathi Sanchit , Piotrkowski Bartosz , Ziółkowski Robert , Janczak Daniel , Krzemiński Jakub , Brosch Michael , Jakubowska Małgorzata TITLE=Electrochemistry of Graphene Nanoplatelets Printed Electrodes for Cortical Direct Current Stimulation JOURNAL=Frontiers in Neuroscience VOLUME=14 YEAR=2020 URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2020.594235 DOI=10.3389/fnins.2020.594235 ISSN=1662-453X ABSTRACT=

Possible risks stemming from the employment of novel, micrometer-thin printed electrodes for direct current neural stimulation are discussed. To assess those risks, electrochemical methods are used, including cyclic voltammetry, square-wave voltammetry, and electrochemical impedance spectroscopy. Experiments were conducted in non-deoxidized phosphate-buffered saline to better emulate living organism conditions. Since preliminary results obtained have shown unexpected oxidation peaks in 0–0.4 V potential range, the source of those was further investigated. Hypothesized redox activity of printing paste components was disproven, supporting further development of proposed fabrication technology of stimulating electrodes. Finally, partial permeability and resulting electrochemical activity of underlying silver-based printed layers of the device were pointed as the source of potential tissue irritation or damage. Employing this information, electrodes with corrected design were investigated, yielding no undesired redox processes.