Electrochemistry of Mitochondrial Isolates on Ultrasonicated Graphene Oxide-Modified Electrodes

Bruno-Mota, Uriel; Chaaben, Safa; Lei, Yuting; Khouri, Andrea; Champagne, Claudia; Ossonon, Benjamin D.; Orgiu, Emanuele; Rodrigue-Gervais, Ian Gaël et Tavares, Ana C. (2025). Electrochemistry of Mitochondrial Isolates on Ultrasonicated Graphene Oxide-Modified Electrodes Electrochimica Acta . DOI: 10.1016/j.electacta.2025.146429. (Sous Presse)

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Résumé

Mitochondria are central to cellular energy production and metabolic regulation, and their dysfunction is linked to various diseases. Understanding mitochondrial activity through electrochemical studies may provide valuable insights into their function, but direct characterization remains challenging due to the complexity of the electron transport chain (ETC) and the need to maintain mitochondrial integrity. While pyrolytic graphite (PGE) and carbon paper electrodes have been used in the past, the inherently weak and poorly resolved voltammetric signals from mitochondria complicate their electrochemistry.

This study investigates the use of PGE modified with graphene oxide obtained by electrochemical exfoliation of graphite (EGO) to enhance the electrochemical signals of isolated human mitochondria. To assess such activity, square wave voltammetry (SWV) was conducted in physiological conditions and compared with metabolic assays. The EGOs flakes and their suspensions obtained after different sonication times, and used in the fabrication of the electrodes were characterized by Scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), and UV-vis spectroscopy.

TEM confirmed mitochondrial structural integrity after interaction with the EGO. Sonication time plays a critical control in mitochondrial viability and activity, as prolonged sonication yields smaller EGO flakes and more graphene oxide quantum dots (GOQD). The flakes improved the interaction between the mitochondria and the electrode’s surface, whereas the GOQD facilitated the electron transfer between the ETC and the electrode, leading to stronger electrochemical signals. We highlight the importance of using SWV in combination with EGO and GOQD to resolve these signals more effectively, overcoming the limitations of typical voltammetry tests.

Type de document:	Article
Mots-clés libres:	Mitochondrial electrochemistry ; Physiological-like conditions ; Mitochondrial respiration ; Graphene oxide ; Graphene oxide quantum dots ; Seahorse analysis ; Square-wave voltammetry
Centre:	Centre Énergie Matériaux Télécommunications
Date de dépôt:	13 mai 2025 13:46
Dernière modification:	13 mai 2025 13:46
URI:	https://espace.inrs.ca/id/eprint/16512

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