Affinity binding of aptamers to agarose with DNA tetrahedron for removal of hepatitis B virus surface antigen.

•Attaching aptamers to agarose through DNA tetrahedral structure to build a novel type of immunosorbent.•This immunosorbent could remove approximately 90% of the HBsAg from human plasma samples.•Better adsorption for samples with high concentration of HBsAg.•The immunosorbents are noncytotoxic.