MULTI STIMULI-RESPONSIVE GRAPHENE OXIDE FOR BIOSENSING APPLICATIONS

The present work tackles the functionalization of graphene oxide (GO) sheets to fabricate multifunctional nanoplatforms whose assembly states can be controlled in response to different stimuli for in-vitro diagnostic application. Specifically, a versatile and smart GO-based substrate - responsive to pH (chemical stimulus), temperature (physical stimulus) and enzymes (biological stimulus) – has been prepared by covalent and/or non-covalent binding respectively of acrylates, acrylamides and dye-labeled peptides onto the GO surfaces. The cooperative effects due to the manifold functionalization have been scrutinized with a multitechnique approach of spectroscopic (Raman, X-ray photoelectron spectroscopy, UV-visible, fluorescence) and microscopic (confocal and atomic force microscopy, scanning electron microscopy) methods, both in solution and at the solid surface. In addition, First Principle and Molecular Dynamics calculations have been performed in parallel with the experiments. Results indicate the promising performances of the developed nanomaterials for the understanding control of the processes, both kinetics and thermodynamics aspects, at the graphene-(bio)molecule interface as well as for the (bio)molecule-target interaction in solution.