Nanomaterials applied in medicine, cultural heritage and chemical sensor technology

Abstract: Herein, we report three different analytical applications of multi-layers of oxidised graphene nanoribbons (GNOs). In the first section of this paper, the most significant results concern the effect of GNOs on the proliferation of NIH3T3 murine fibroblasts. Results show that GNOs represent the most biocompatible nanomaterials (compared with other ones, such as carbon black, single-wall carbon nanotubes pristine and treated carbon nanotubes) to use as nano-carrier in nanomedicine. In fact, GNO has been successfully used 'in vitro', for the transfection of the viral genome, particularly that relating to the hepatitis A virus (HAV - that normally is not able to replicate in some cell lines), in mammalian cells (BGM-Buffalo Green Monkey). The cell imaging is performed using the auto-fluorescence property of GNO (without additional steps of chemical conjugation with fluorescent probes), one of many extraordinary optical features exhibited by this new nanomaterial. In the second section, GNOs have been functionalised with ionic liquids (ILs) in order to obtain nanocomposite materials with enhanced physical-chemical properties. Latter are very useful for the restoration of modern tracing papers, obtained by refining forced (suffering from typical problems due to poor preservation of cultural heritage, such as gaps, tears and flaps). The results show that the tear is to be newly 'consolidated' and GO/ILs create bridges that make solidify the flaps. The optical microscope images show encouraging results because they do not appreciate significant variations in the optical properties of the substrate, after the treatment. In the third section, ionic liquids are used to disperse GNO to obtain stable and homogeneous nano-emulsions, to cast directly on the Screen-Printed Electrode (SPE) surfaces. New chemical sensors for the selective electrochemical detection of (a) neurotransmitters and (b) NADH (for the assembly of dehydrogenase biosensors) have also been assembled.