The hybrid nanobiointerface between nitrogen-doped graphene oxide and lipid membranes: a theoretical and experimental study

In this study, we present a comparison between graphene oxide (GO) and nitrogen-doped GO (N-GO) in terms of spectroscopic properties and biomolecule-binding potentiality features. Specifically, GO nanosheets, both in aqueous dispersion and in solid state, were successfully modified with different amino-containing moieties, in order to obtain graphene-based nanostructures able to respond to chemical stimuli (e.g., pH) and with tunable surface properties. The physisorption of dye-labelled lipid vesicles loaded with curcumin, was scrutinised both theoretically and experimentally. The energetics of the hybrid lipid membrane-curcumin-GO interface at different pH values, representative respectively of physiological (7.4) and pathological (5.5) environment, were estimated by molecular dynamics (MD) simulations. The GO and GO-N samples characterization by Raman, fluorescence, and UV-vis spectroscopies, as well as confocal microscopy demonstrated promising features of the (N-)GO/lipid platforms for fluorescence imaging and drug delivery applications.