Vajrala Venkata Suresh, Saunier Valentin, Nowak Lionel G, Flahaut Emmanuel, Bergaud Christian, Maziz Ali
Laboratory for Analysis and Architecture of Systems (LAAS), CNRS, Toulouse, France.
Centre de Recherche Cerveau et Cognition (CerCo), CNRS, Toulouse, France.
Front Bioeng Biotechnol. 2021 Nov 26;9:780197. doi: 10.3389/fbioe.2021.780197. eCollection 2021.
In this study, we report a flexible implantable 4-channel microelectrode probe coated with highly porous and robust nanocomposite of poly (3,4-ethylenedioxythiophene) (PEDOT) and carbon nanofiber (CNF) as a solid doping template for high-performance neuronal recording and stimulation. A simple yet well-controlled deposition strategy was developed electrochemical polymerization technique to create a porous network of PEDOT and CNFs on a flexible 4-channel gold microelectrode probe. Different morphological and electrochemical characterizations showed that they exhibit remarkable and superior electrochemical properties, yielding microelectrodes combining high surface area, low impedance (16.8 ± 2 MΩ µm at 1 kHz) and elevated charge injection capabilities (7.6 ± 1.3 mC/cm) that exceed those of pure and composite PEDOT layers. In addition, the PEDOT-CNF composite electrode exhibited extended biphasic charge cycle endurance and excellent performance under accelerated lifetime testing, resulting in a negligible physical delamination and/or degradation for long periods of electrical stimulation. testing on mouse brain slices showed that they can record spontaneous oscillatory field potentials as well as single-unit action potentials and allow to safely deliver electrical stimulation for evoking field potentials. The combined superior electrical properties, durability and 3D microstructure topology of the PEDOT-CNF composite electrodes demonstrate outstanding potential for developing future neural surface interfacing applications.
在本研究中，我们报告了一种柔性可植入4通道微电极探针，其涂覆有聚（3,4-乙撑二氧噻吩）（PEDOT）和碳纳米纤维（CNF）的高度多孔且坚固的纳米复合材料，作为用于高性能神经元记录和刺激的固体掺杂模板。开发了一种简单但可控的沉积策略——电化学聚合技术，以在柔性4通道金微电极探针上创建PEDOT和CNF的多孔网络。不同的形态和电化学表征表明，它们具有显著且优异的电化学性能，产生的微电极具有高表面积、低阻抗（1 kHz时为16.8±2 MΩ·μm）和增强的电荷注入能力（7.6±1.3 mC/cm），超过了纯PEDOT层和复合PEDOT层。此外，PEDOT-CNF复合电极在加速寿命测试中表现出延长的双相电荷循环耐久性和优异性能，在长时间电刺激下物理分层和/或降解可忽略不计。在小鼠脑片上的测试表明，它们可以记录自发振荡场电位以及单单位动作电位，并允许安全地施加电刺激以诱发场电位。PEDOT-CNF复合电极兼具的优异电学性能、耐久性和三维微观结构拓扑，为未来神经表面接口应用的开发展现出巨大潜力。
