Single layer graphene functionalized MEA for enhanced detection of neuronal network development

The exploitation of graphene for neuro-interfacing applications requires a complete, yet missing, understanding of neuron-graphene interaction. Here, we have explored the interplay between the carbon based interface and neuronal networks during the complete developmental phase at whole network scale. To this purpose, we have, first, successfully transferred large grains single layer graphene (LG-SLG) via wet etching onto commercial planar 60 electrode devices; then, we have compared to control the neuronal growth on the functionalized devices, recording the spontaneous activity up to completion of network maturation, i.e., from 7 to 25 days-in-vitro. The immunohistochemistry investigation demonstrated a comparable morphology of the neuronal network on SLG and control substrates but with a higher number of neurons on SLG. The most striking results of the electrophysiological investigation were the observation of spikes and bursts activity at an earlier developmental phase and of strongly synchronized neuronal networks on SLG-MEA versus control, suggesting an improved neuron/electrode coupling. These observations agree with our previous study of single neuron synaptogenesis by patch clamp, where earlier synaptogenesis on SLG compared to the control was detected. The results have been corroborated by the firing and bursting analysis showing higher and statistically significant values on SLG-MEA.