Poly-cytosine DNA as a High-Affinity Ligand for Inorganic Nanomaterials

Attaching DNA to nanomaterials is the basis for DNA-directed assembly, sensing, and drug delivery using such hybrid materials. Poly-cytosine (poly-C) DNA is a high affinity ligand for four types of commonly used nanomaterials, including nanocarbons (graphene oxide and single-walled carbon nanotubes), transition metal dichalcogenides (MoS₂ and WS₂), metal oxides (Fe₃O₄ and ZnO), and metal nanoparticles (Au and Ag). Compared to other homo-DNA sequences, poly-C DNA has the highest affinity for the first three types of materials. Using a diblock DNA containing a poly-C block to attach to surfaces, the target DNA was successfully hybridized to the other block on graphene oxide more efficiently than that containing a typical poly-A block, especially in the presence of non-specific background DNA, proteins, or surfactants. This work provides a simple solution for functionalizing nanomaterials with non-modified DNA and offers new insights into DNA biointerfaces.