Aptamer functionalized magnetic graphene oxide nanocomposites for highly selective capture of histones

The binding coverage of aptamer was an important restricted factor for aptamer-based affinity enrichment strategy for capturing target molecules. Herein, we designed and prepared aptamer functionalized graphene oxide based nanocomposites (GO/NH₂ -NTA/Fe₃ O₄ /PEI/Au), and the coverage density of aptamer was high to 33.1 nmol/mg. The high aptamer coverage density was contributed to the large surface area of graphene oxide. The successive modification of Nα,Nα-Bis(carboxymethyl)-L-lysine, magnetic nanoparticles, polyethylenimine, and Au nanoparticles ensured the histone purification with fast speed and high purity. Histones could be captured rapidly and specifically from nucleoproteins by our aptamer based purification strategy, while traditional acid-extraction could not specifically enrich histones. Compared with traditional acid-extraction method, rapid and efficient discovery of histones and their post-translational modifications, such as several kinds of methylation at H3.1K9 and H3.1K27, were achieved confidently. It demonstrated that our aptamer functionalized magnetic graphene oxide nanocomposites have a great potential for histone analysis.