Graphene-based neural electrodes: from materials and device fabrication to properties

Neural electrodes serve as a conduit for the purpose of facilitating electrophysiological communication between neurons and external electronic devices. These electrodes are extensively utilized in both neuroscientific research and in the domains of neural prosthetics and neuromodulation practices. Recently, graphene and its numerous derivatives have emerged as a transformative material in bioelectronics and electrochemical applications. Depending on the device fabrication process and preferred graphene derivative, graphene-based neural electrodes can offer fatigue-resistant flexibility, high electrical conductivity, excellent optical transparency (97.7%), increased specific surface area, superior electrochemical durability, composability, and advanced surface functionalization properties, which can make them an ideal choice for their intended in vivo or in vitro applications. In this review, we comparatively summarize the existing work on graphene and graphene related material-based electrochemical neural electrodes through the key studies of diverse approaches to provide an overview of the field, highlight the motivations behind the research, and identify potential improvement strategies for future investigations.