Growth and origami folding of DNA on nanoparticles for high-efficiency molecular transport in cellular imaging and drug delivery.

A novel three-dimensional (3D) superstructure based on the growth and origami folding of DNA on gold nanoparticles (AuNPs) was developed. The 3D superstructure contains a nanoparticle core and dozens of two-dimensional DNA belts folded from long single-stranded DNAs grown in situ on the nanoparticle by rolling circle amplification (RCA). We designed two mechanisms to achieve the loading of molecules onto the 3D superstructures. In one mechanism, ligands bound to target molecules are merged into the growing DNA during the RCA process (merging mechanism). In the other mechanism, target molecules are intercalated into the double-stranded DNAs produced by origami folding (intercalating mechanism). We demonstrated that the as-fabricated 3D superstructures have a high molecule-loading capacity and that they enable the high-efficiency transport of signal reporters and drugs for cellular imaging and drug delivery, respectively.