Site-Specific Metallization of Multiple Metals on a Single DNA Origami Template

Abstract

This work examines the selective deposition of two different metals on a single DNA origami template that was designed and assembled to direct the deposition. As a result, we were able to direct copper and gold to predesignated locations on the template, as verified by both compositional and morphological data, to form a heterogeneous Cu-Au junction. Seeding and deposition were performed in sequential steps. An enabling aspect of this work was the use of an organic layer or "chemical mask" to prevent unwanted deposition during the deposition of the second metal. In light of recent efforts in the field, the ability to localize components of different composition and structure to specific sections of a DNA template represents an important step forward in the fabrication of nanostructures based on DNA templates.

Metallic Nanostructures Based on DNA Nanoshapes

“…Harb et al pushed the boundaries of this technique even further in 2014, when they developed a method to specifically metallize the same origami structure with two different metals [96]. The key aspect of this work was the use of octadecanethiol in between the site-specific Au plating and unspecific Cu plating.…”

“…However, the granular appearance of the structures is still one of the intrinsic problems of the electrodeless plating method. Still, when compared to the initial research on ssDNA, dsDNA and tile-based DNA-structures that face the same problem of granular appearance, DNA origami offers a more versatile toolset to fabricate defined size structures for both electronics and plasmonic applications, e.g., for SERS, as demonstrated by Pilo-Pais et al [94], or for the fabrication of double metal junctions by Harb et al [96]. …”

“…( e ) Structures with just a single AuNP resulted in an insignificant SERS signal [94]. ( f ) A single origami bar metallized with both gold and copper on either side [96]. ( g – i ) T-shaped DNA structures with AuNPs bound to one branch, both branches (inset in (h)) and only on the edges of the T-branches (inset in (i)).…”

“…Copyright American Chemical Society, 2011; (d–e) are reproduced with permission from [94]. Copyright American Chemical Society, 2014; (f) is reproduced with permission from [96]. Copyright American Chemical Society, 2014; (g–i) are reproduced with permission from [91].…”

The assemble, grow and lift-off (AGLO) strategy to construct complex gold nanostructures with pre-designed morphologies

“…30,31 Other methods require preimmobilizing DNA origami structures onto at substrates (mica, silica, etc. ), [45][46][47][48][49] which would prevent further scale-up, functionalization and application of the resulting metallic structures. Recently, a DNA origami mould method has been developed to cast metallic structures inside the DNA molds.…”