Modular Assembly of Plasmonic Nanoparticles Assisted by DNA Origami

Abstract

Arraying noble metal nanoparticles with nanoscale features is an important way to develop plasmonic devices with novel optical properties such as plasmonic chiral metamolecules, optical waveguides, and so forth. Along with top-down methods of fabricating plasmonic nanostructures, solution-based self-assembly provides an alternative approach. There are mainly two routes to organizing metal nanoparticles via self-assembly. One is directly linking nanoparticles through linker molecules, and the other is using nanoparticles to decorate a preformed template. We combine these two routes and herein report a strategy for the DNA origami-assisted modular assembly of gold nanoparticles into homogeneous and heterogeneous plasmonic nanostructures. For each module, we designed W-shaped DNA origami with two troughs as two domains. One domain is used to host a gold nanoparticle, and the other domain is designed to capture another gold nanoparticle hosted on a different module. By simply tuning the sequences of capture DNA strands on each module, gold nanoparticles including spherical and rod-shaped gold nanoparticles (denoted as AuNPs and AuNRs) could be well organized in a predefined manner to form versatile plasmonic nanostructures. Since the interparticle distances could be precisely controlled at the nanoscale, we also studied the plasma coupling among the assembled plasmonic nanostructures. This modular assembly strategy represents a simple yet general and effective design principle for DNA-assembled plasmonic nanostructures.

Assembly of Gold Nanorods into Chiral Plasmonic Metamolecules Using DNA Origami Templates

“…Various types of responses and functionalizes can be incorporated into the lock strands that define the chiral state of the origami template ( Figure 1B) 24, 25,26,31 . For static assemblies, simpler block-shaped templates are often sufficient 14,45,46,47 .…”

Chiral Ag and Au Nanomaterials Based Optical Approaches for Analytical Applications

“…DNA origami is a robust and important technology, which allows precise arrangement of Ag and Au nanoparticles in designable assemblies . For example, chiral Au nanorod dimers with various 3D configurations on bifacial DNA origami were constructed 40c. The Au nanorods are located accurately on both sides of the bifacial DNA origami to generate discrete 3D nanoarchitectures.…”

“…Stair‐like and coil‐like chiral architectures with purposed handedness were fabricated separately by changing DNA strands. Asymmetric tetramer composed of four Au nanoparticles (diameter of 20 nm) were precisely organized on a rigid addressable DNA origami template, which allows the formation of left‐ and right‐handed structures 40b. Upon changing the nanostructure, the CD curve varies, mainly because the chiral response of nanoassemblies is related to the resonance coupling between/among the nanoparticles.…”

“…It depends on the orientation and dimensional position of Au nanorods. For example, “X”‐shaped dimer has a stronger CD response than “T”‐shaped counterpart 40c. When compared to end‐to‐end dimers, side‐to‐side dimers have stronger CD signals, mainly because the two nanorods are twisted.…”

DNA-Assisted Assembly of Gold Nanostructures and Their Induced Optical Properties

“…CTAB-capped AuNRs were coated with a thin gold layer via overgrowth for binding to thiol-DNA and the resultant DNA-AuNR conjugates were immobilized onto two arms of the DNA tiles to form an adjustable angle, ranging from 0° (side by side arrangement) to 60°, 90°, and 180° (end-to-end arrangement). Moreover, Wang’s group [53,54] recently combine AuNPs and AuNRs to construct a series of well-defined heterostructures by using DNA origami clamps (Figure 2D), which greatly expanded the utility of DNA origami as a tool for building more complex nanoarchitectures. Inspired from the preceding studies in the literature, the strongly plasmonic couples always happens in the vicinity of the sharp tips [55], and many researchers have been dedicated to rationally design and fabricate sharp tips containing metallic nanostructures.…”