Surface potential modulates fibronectin adsorption and molecular interaction on graphene-based materials.

This article investigates the role of surface potential (SP) in modulating protein interactions on graphene-based materials (GBMs), specifically comparing graphene oxide (GO) and reduced graphene oxide (RGO). GO and RGO substrates were prepared and characterized, revealing distinct surface potentials of +120 mV for GO and +60 mV for RGO, linked to differences in oxygen-containing functional groups and hydrophilicity. Using fibronectin (FN) as a model protein, the study demonstrated that RGO's lower surface potential and hydrophobicity promoted approximately threefold greater FN adsorption with compact globular conformations, whereas GO's higher surface potential favored elongated fibrillar FN structures with lower adsorption. Molecular docking simulations supported these findings by showing stronger and more stable FN binding to RGO than GO, highlighting the influence of surface potential on protein adsorption affinity, binding stability, and conformational organization. The results emphasize surface potential as a critical parameter in designing graphene-based biomaterials with tailored biointerface properties for biomedical applications.