Parkinson’s disease (PD) is the second most common neurodegenerative disease in the United States after Alzheimer’s disease (AD). To help understand the electrophysiology of these diseases, N27 neuronal cells have been used as an in vitro model. In this study, a flexible graphene-based biosensor design is presented. Biocompatible graphene was manufactured using a liquid-phase exfoliation method and bovine serum albumin (BSA) for further exfoliation. Raman spectroscopy results indicated that the graphene produced was indeed few-layer graphene (FLG) with (ID/IG)Graphene= 0.11. Inkjet printing of this few-layer graphene ink onto Kapton polyimide (PI) followed by characterization via scanning electron microscopy (SEM) showed an average width of ≈868 µm with a normal thickness of ≈5.20 µm. Neuronal cells were placed on a thermally annealed 3D printed graphene chip. A live–dead cell assay was performed to prove the biosensor biocompatibility. A cell viability of approximately 80% was observed over 96 h, which indicates that annealed graphene on Kapton PI substrate could be used as a neuronal cell biosensor. This research will help us move forward with the study of N27 cell electrophysiology and electrical signaling.