Interaction Of Graphene Oxide With Nuclear Dyes And Its Application

Graphene oxide (GO) is a oxide of graphene. It is a2D material only with one layer of carbon atoms in thickness separated from graphite by two physicists from the university of Chester in2004, it is the thinnest materials. GO has remarkable high specific surface area, the different types of oxygen-containing functional groups on the basal plane and the sheet edge such as hydroxyl, carboxyl and ether likage allows GO to assembly with both organic and inorganic materials in non-covalent, covalent and ionic manner in solution. GO is a kind of new carbon materials which shows excellent performance, providing potential applications in energy storage, molecular imaging, biological, chemical sensing and drug delivery etc.Owning to its high specific surface area, GO can act as an efficient quencher of an organic fluorophore based on either an energy transfer or electron transfer process. We applied this method to detect nucleic acid with nucleic acid dyes. The nucleic acid dyes that we chose could recognize deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), but the strong background fluorescence resulted in low recognition efficiency. Using GO as an efficient quencher can eliminate the background fluorescence of nucleic dyes. Upon the addition of DNA or RNA, the nucleic dyes can be competed down from the GO’s surface, thus remarkable fluorescent enhancement can be observed and improve the efficiency of detection.Meanwhile, nucleic dyes carry positive charges and are soluble in water or cell culture medium, so it has no capacity to cross cellular membranes, which limits theirs applications in biological detection in vivo. Graphite oxide can carry the nucleic acid dye into the cell depending on energy by endocytosis of cells, realizing the detection in vivo. In the article, we chose two kinds of nucleic acid dyes:a ruthenium (II) complex and the propidium iodide (PI). They underwent the non-covalent interaction with GO in vitro and then applied to stain cells. Fluorescence was detected under one-photon excitation by spectral confocal multiphoton microscopes and digestion test demonstrated that the GO based hybrid can stain in cell nucleus in vivo, which was consistent with the results in vitro. So after the interaction with GO, the nucleic acid dyes not only achieve the efficient detection in vitro but also achieve the detection in vivo. All these provide a basis for us to research efficient of graphene oxide, biologically targeted nanoparticles drug delivery system and biological sensors.