Noncovalent DNA decorations of graphene oxide and reduced graphene oxide toward water-soluble metal–carbon hybrid nanostructuresviaself-assembly

Abstract

Non-covalent DNA decorations on the basal planes of graphene oxide and reduced graphene oxide nanosheets are realized. The resulting DNA–carbon bioconjugates (DNA–GO or DNA–RGO) bearing multiple thiol groups tagged on DNA strands are then employed to scaffold the two-dimensional self-assembly of gold nanoparticles (AuNPs) into metal–carbon hybrid nanostructures (namely AuNP–DNA–GO or AuNP–DNA–RGO) that may find important applications in various aspects. The resulting heteronanostructures incorporating metal nanoparticles obtained by self-assembly are highly stable and water-soluble, and can be easily isolated by gel electrophoresis to guarantee high purity. Thanks to the noncovalent features of this method, either GO or RGO do not suffer from any permanent alterations of their structures and properties. In addition, the nanoparticles still maintain their optical absorbance after being assembled, and the assembly process is highly specific. This self-assembly based method for constructing heterostructured materials is excellent at overcoming any incompatibilities between nanoparticle syntheses and the formation of hybrid structures. As a result, this strategy is easily adaptable to various other materials other than gold nanoparticles and also favors the combinatorial assembly of multiple nanophases on a single nanosheet.