Objective. There is a growing interest in the use of carbon and its allotropes for microelectrodes in neural probes because of their inertness, long-term electrical and electrochemical stability, and versatility. Building on this interest, we introduce a new electrode material system consisting of an ultra-thin monoatomic layer of graphene (Gr) mechanically supported by a relatively thicker layer of glassy carbon (GC). Approach. Due to its high electrical conductivity and high double-layer capacitance, Gr has impressive electrical and electrochemical properties, two key properties that are useful for neural recording and stimulation applications. However, because of its two-dimensional nature, Gr exhibits a lack of stiffness in the transverse direction and hence almost non-existent flexural and out-of-plane rigidity that will severely limit its wider use. On the other hand, GC is one of carbon’s important allotropes and consists of three-dimensional microstructures of Gr fragments with a natural molecular similarity to Gr. Further, GC has exceptional chemical inertness, good electrical properties, high electrochemical stability, purely capacitive charge injection, and fast surface electrokinetics coupled with lithography patternability. This makes GC an ideal candidate for addressing Gr’s lack of out-of-plane rigidity through providing a matching sturdier and robust mechanical backing. Combining the strengths of these two allotropes of carbon, we introduce a new neural probe that consists of ∼1 nm thick layer of patterned Gr microelectrodes supported by another layer of 3–5 μm thick patterned GC. Main results. We present the fabrication technology for the new Gr on GC (graphene on glassy carbon) microelectrodes and the accompanying pattern transfer technology on flexible substrate and report on the bond between these two allotropes of carbon through FTIR, surface morphology through SEM, topography through atomic force microscopy, and microstructure imaging through scanning transmission electron microscopy. A long-term (18 weeks) in vivo study of the use of these Gr on GC microelectrodes assessed the quality of the electrocorticography-based neural signal recording and stimulation through electrophysiological measurements. The probes were demonstrated to be functionally and structurally stable over the 18 week period with minimal glial response—the longest reported so far for Gr-based microelectrodes. Significance. The Gr on GC microelectrodes presented here offers a compelling case for expanding the potentials of Gr-based technology in the broad areas of neural probes.

客观的。由于碳及其同素异形体具有惰性、长期电和电化学稳定性以及多功能性，因此人们对将碳及其同素异形体用于神经探针中的微电极越来越感兴趣。基于这种兴趣，我们引入了一种新的电极材料系统，该系统由由相对较厚的玻璃碳 (GC) 层机械支撑的超薄石墨烯 (Gr) 单原子层组成。方法。由于其高导电性和高双层电容，Gr 具有令人印象深刻的电学和电化学特性，这两个关键特性可用于神经记录和刺激应用。然而，由于其二维性质，Gr 在横向上表现出缺乏刚度，因此几乎不存在弯曲和面外刚度，这将严重限制其更广泛的应用。另一方面，GC 是碳的重要同素异形体之一，由 Gr 碎片的三维微观结构组成，与 Gr 具有天然的分子相似性。此外，GC 具有出色的化学惰性、良好的电学特性、高电化学稳定性、纯电容性电荷注入以及与光刻图案化相结合的快速表面电动势。这使得 GC 成为解决 Gr 缺乏平面外刚度的理想选择，通过提供匹配的更坚固和坚固的机械背衬。结合这两种碳同素异形体的强度，我们引入了一种新的神经探针，它由约 1 nm 厚的图案化 Gr 微电极层组成，由另一层 3-5μ m 厚的图案化 GC。主要结果。我们介绍了新型Gr on GC（玻璃碳上的石墨烯）微电极的制造技术以及柔性基板上的伴随图案转移技术，并通过 FTIR 报告了碳的这两种同素异形体之间的键、通过 SEM 的表面形态、通过原子力的形貌显微镜和通过扫描透射电子显微镜进行的微观结构成像。这些Gr 在 GC 上使用的长期（18 周）体内研究微电极通过电生理测量评估了基于皮层电图的神经信号记录和刺激的质量。这些探针在 18 周内表现出功能和结构稳定，胶质反应最小——迄今为止报道的最长的基于 Gr 的微电极。意义。此处介绍的GC微电极上的Gr为扩展基于 Gr 的技术在神经探针的广泛领域的潜力提供了令人信服的案例。