Creating metamaterial building blocks with directed photochemical metallization of silver onto DNA origami templates

Abstract

DNA origami can be used to create a variety of complex and geometrically unique nanostructures that can be further modified to produce building blocks for applications such as in optical metamaterials. We describe a method for creating metal-coated nanostructures using DNA origami templates and a photochemical metallization technique. Triangular DNA origami forms were fabricated and coated with a thin metal layer by photochemical silver reduction while in solution or supported on a surface. The DNA origami template serves as a localized photosensitizer to facilitate reduction of silver ions directly from solution onto the DNA surface. The metallizing process is shown to result in a conformal metal coating, which grows in height to a self-limiting value with increasing photoreduction steps. Although this coating process results in a slight decrease in the triangle dimensions, the overall template shape is retained. Notably, this coating method exhibits characteristics of self-limiting and defect-filling growth, which results in a metal nanostructure that maps the shape of the original DNA template with a continuous and uniform metal layer and stops growing once all available DNA sites are exhausted.

Interfacial and Bulk Assembly of Anisotropic Gold Nanostructures: Implications for Photonics and Plasmonics

“…For characterization of the morphology and size distribution, PEG-AuNSts are deposited on RCA Cleaned n-type Silicon. 53 Then, a field emission scanning electron microscopy (FE-Teneo, operated at 20kV) in high vacuum mode is used to image PEG-AuNSts. Representative SEM images of PEG-AuNTs and PEG-AuNOh are shown in Figure 2(a, b) after the separation process and grafting.…”

Salt Mediated Self-Assembly of Poly(ethylene glycol)-Functionalized Gold Nanorods

“…We thus, examine this approach to assemble AuNRs, and apply surface sensitive synchrotron X-ray techniques including specular X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS) to characterize the assembly of AuNRs at the vapor/liquid interface. We propose that the method presented here can be potentially further extended to assemble a variety of complex nanostructures such as nanotriangles, nanocubes and other nanostructure shapes 41–43 .…”

Salt Mediated Self-Assembly of Poly(ethylene Glycol)-Functionalized Gold Nanorods

“…We propose that the method presented here can be potentially further extended to assemble a variety of complex nanostructures such as nanotriangles, nanocubes and other nanostructure shapes. [34][35][36] Materials and Methods (D) Small angle X-ray scattering (SAXS) intensity profiles of bare AuNR (red triangles) and PEG5K-AuNR (blue circles). The black solid line is a best fit to SAXS data using the form factor of circular cylinder particles not accounting for the polydispersity of the NRs.…”