Pattern Recognition Directed Assembly of Plasmonic Gap Nanostructures for Single-Molecule SERS

Abstract

Gold nanocubes (AuNCs) with tunable localized surface plasmon resonance properties are good candidates for plasmonic gap nanostructures (PGNs) with hot spots (areas with intense electric field localization). Nevertheless, it remains challenging to create shape-controllable nanogaps between AuNCs. Herein, we report a DNA origami directed pattern recognition strategy to assemble AuNCs into PGNs. By tuning the position and number of capture strands on the DNA origami template, different geometrical configurations of PGNs with nanometer-precise and shape-controllable gaps are created. The localized field enhancement in these gaps can generate hot spots that are in accordance with finite difference time domain simulations. Benefiting from the single Raman probe molecule precisely anchored at these nanogaps, the dramatic enhanced electromagnetic fields localized in hot spots arouse stronger single-molecule SERS (SM-SERS) signals. This method can be utilized in the design of ultrahigh-sensitivity photonic devices with tailored optical properties and SERS-based applications.

Recent Advances in DNA Origami-Engineered Nanomaterials and Applications

“…Niu et al reported an interesting strategy to create shape-controllable nanogaps between Au nanocubes (AuNCs) using DNA origami (see Figure 34H). 509 Due to the anisotropic nature of the AuNCs, their vertices, edges, and faces allowed for the creation of richer configurations of nanogaps than isotropic spherical AuNPs, together with significantly enhanced electromagnetic fields in these nanogaps. By tuning the position and number of capture strands on the DNA origami, pattern recognition was enabled to assemble AuNCs in different geometrical configurations with nanoscale precision and shape-controllable gaps.…”

“…(H) DNA origami-directed pattern recognition strategy to assemble AuNCs for single-molecule SERS. Reproduced with permission from ref . Copyright 2022 American Chemical Society.…”

Quinine-Fabricated Surface-Enhanced Raman Spectroscopy Chiral Sensing Platform Enables Simultaneous Enantioselective Discrimination and Identification of Aliphatic Amino Acids

“…17 However, the regular SERS detection performed at colloidal nanoparticles and solid substrates always faces the challenge of precisely fabricating the plasmonic gaps down to subnanometer distance and detailed local nanostructures. 18 It is worth noting that aliphatic amino acid molecules usually possess low Raman scattering cross sections and low specific affinity to noble metal surfaces. As a consequence, it is challenging to capture them into the plasmonic gaps to directly obtain their own SERS signals, let alone to detect molecular chirality.…”

“…When molecules are located in these sub-nanometer plasmonic gap regions, rich chemical and structural information of the molecules is accessible, allowing for ultra-sensitive detection down to a single molecule . However, the regular SERS detection performed at colloidal nanoparticles and solid substrates always faces the challenge of precisely fabricating the plasmonic gaps down to sub-nanometer distance and detailed local nanostructures . It is worth noting that aliphatic amino acid molecules usually possess low Raman scattering cross sections and low specific affinity to noble metal surfaces.…”

Embossed Template Induced Particles Assembly for Heterostructures and the Application in High‐Security Encryption

“…[6,7] So far, a variety of methods have been reported to modulate the particles assembly, such as through modified molecular mediation, [8,9] electric, [10] magnetic, [11] light [12] or fluidic [13] field direction, and interfacial selfassembly, [14] as well as template induced assembly. [15][16][17] Among these strategies, template induced particles assembly has shown remarkable advantage for deterministic placement of large spectrum of materials from micro-to nanometer dimensions and efficient integration with substrates, showing great significance in fabricating advanced devices in the fields of optics, [18] electronics, [19] biodetection, [20] etc. Especially, template-induced multicomponents assembly, with promising potential in superior micro-/nanodevices with new functionalities by utilizing interparticle electromagnetic coupling or other synergistic effects, [21,22] have been witnessed with great progress in the past several years.…”