Desorption of single-stranded nucleic acids from graphene oxide by disruption of hydrogen bonding.

Graphene oxide (GO) is known to interact with single-stranded nucleic acids through pi-stacking interactions and hydrogen bonds between the nucleobases and the hexagonal cells of GO. It also quenches the fluorescence when the fluorophore comes near to the GO mesh. When single-stranded (ss) regions of either DNA or RNA are present, those regions were adsorbed onto the surface of GO with a quenching of fluorescence located proximally to the GO surface. We demonstrated that bound single-stranded nucleic acids can be readily dissociated from GO by disrupting hydrogen bonding with urea, which was confirmed with fluorescence measurement and gel electrophoresis. Hydrogen bonding mainly contributes to the interaction between GO and single-stranded nucleic acids such as ssDNA and RNA. The GO-coated mesoporous silica nanoparticles (GO-MSNs) were synthesized for better separation of RNAs from cells. Cellular RNAs were readily adsorbed and eluted with ease by using GO-MSN and urea, respectively, demonstrating that GO-MSN and urea elution is a facile RNA extraction method.