Double-stranded DNA-graphene hybrid: preparation and anti-proliferative activity

Herein, we demonstrate a simple method to prepare graphene dispersions in an aqueous solution of DNA by the sonication of bulk graphite. The use of a commercial double-stranded DNA as a stabilizer for graphite exfoliation without any chemical modification is presented. The high energy sound waves cleave a double-stranded DNA into two single-stranded DNAs. UV-vis spectral studies show that the nucleobases in the product are intact. Atomic force microscopy studies reveal that the size of the obtained nanosheets can be enriched into smaller lateral dimensions using centrifugation. Raman spectroscopy suggests that the defects found in the nanosheets induced by the sonication are edge defects, whereas the bodies of the sheets remain relatively defect free. The graphene dispersions are extremely stable over a wide range of pH values, possessing high negative zeta potential values. The anti-proliferative effect observed through in vitro cytotoxicity studies is supported by in vivo studies using the zebrafish human tumor xenograft model. The migration of cancer cells in zebrafish embryos are inhibited by the graphene nanosheet dispersion. The negatively charged nanosheet serves as a platform for the adsorption of gold nanoparticles with positively charged surfaces.