Graphene-lipids interaction: towards the fabrication of a novel sensor for biomedical uses

In this work we investigate the use of graphene as transducer in a novel biosensor for biomedical uses, in which electroactive membrane proteins would serve as biological recognition elements. Membrane proteins maintain their functionalities only if embedded in the cell membrane, so it is necessary to develop a system, which mimics their native environment. This study is focused on surface treatments of graphene to improve its biocompatibility and a first investigation of its interaction with liposomes, which rupture and spread to form a Supported Lipid Bilayer under specific surface conditions. The first step involved the characterization of the graphene membranes synthesized by Chemical Vapor Deposition, using several techniques to determine their morphological and structural properties. From these investigations, the CVD-synthesized graphene resulted to be mono-to few-layer. Next, the interaction of graphene with lipids (1,2-dioleoyl-sn-glicero-3-phosphocholine), in particular the formation of a supported lipid bilayer due to the liposome spreading, was investigated via electrochemical impedance spectroscopy. This indicated the presence of a stable insulating lipid layer on the graphene surface after liposome incubation.