The use of graphene-based materials to engineer sophisticated biosensing interfaces that can adapt to the central nervous system requires a detailed understanding of how such materials behave in a biological context. Graphene’s peculiar properties can cause various cellular changes, but the underlying mechanisms remain unclear. Here, we show that single-layer graphene increases neuronal firing by altering membrane-associated functions in cultured cells. Graphene tunes the distribution of extracellular ions at the interface with neurons, a key regulator of neuronal excitability. The resulting biophysical changes in the membrane include stronger potassium ion currents, with a shift in the fraction of neuronal firing phenotypes from adapting to tonically firing. By using experimental and theoretical approaches, we hypothesize that the graphene–ion interactions that are maximized when single-layer graphene is deposited on electrically insulating substrates are crucial to these effects.
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We thank M. Lazzarino, S. Dal Zilio and the Facility of NanoFabrication of IOM of Trieste for experimental assistance in the fabrication of suspended SLG and FIB analysis, and N. Secomandi and R. Rauti for assistance in imaging. We thank A. Laio, G. Scoles, A. Nistri and B. Cortés-Llanos for discussion. This paper is based on work supported by the European Union Seventh Framework Program under grant agreement no. 696656 Graphene Flagship and no. 720270 Human Brain Project Flagship, and by the Flanders Research Foundation (grant no. G0F1517N). M.P., as the recipient of the AXA Chair, is grateful to the AXA Research Fund for financial support. M.P. was also supported by the Spanish Ministry of Economy and Competitiveness MINECO (project CTQ2016-76721-R), by the University of Trieste and by Diputación Foral de Gipuzkoa program Red (101).
The authors declare no competing interests.
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Pampaloni, N.P., Lottner, M., Giugliano, M. et al. Single-layer graphene modulates neuronal communication and augments membrane ion currents. Nature Nanotech 13, 755–764 (2018). https://doi.org/10.1038/s41565-018-0163-6
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