Reduced graphene oxide aerogel with packaged TiO2 nanoparticles as a promising adsorbent for the separation of DNA from human whole blood

A three-dimensional reduced graphene oxide porous aerogel with packaged TiO 2 nanoparticles was prepared by a simple one-step self-assembly in a water bath at a mild temperature. Herein, we overcame the aggregation of graphene layers by forming three-dimensional architecture, and utilized TiO 2 aggregates as blocks to make the composite surface uneven. The extended aromatic areas contribute to DNA adsorption by aromatic stacking and hydrophobic interaction. The obtained composite exhibited porous structure and was positively charged at a low pH. The composite exhibited a high capacity of 890.1 mg g −1 and an adsorption efficiency of 98.4% to DNA at pH 3, however, bovine serum albumin at the same concentration level was hardly adsorbed. The composite showed favorable selectivity to DNA against protein even designed in such a simple manner. The retained DNA could be stripped by using a 0.04 mol L −1 Britton–Robinson buffer at pH 10, giving rise to a recovery of 96.3%. The DNA was isolated from human whole blood to be used as templates for PCR amplification successfully. This illustrates that DNA with high purity and quality was obtained.