Gold Nanopolyhedron-Based Superlattice Sheets as Flexible Surface-Enhanced Raman Scattering Sensors for Detection of 4-Aminothiophenol

Abstract

The self-assembly of plasmonic building blocks into superlattices has emerged as a promising route to fabricate metamaterials with customizable nanoscale architecture and collective properties. However, self-assembly of such plasmonic superlattice has proven challenging, owing to the low packing fraction, complex interparticle forces, and local heterogeneity. Besides, the conventional assembly of small nanoparticles usually exhibits localized defects and uncontrollable electromagnetic field distribution, limiting its functionality for real-world application. Here, we report on the self-assembly of multifacet gold nanopolyhedron (AuNPH) into high-quality giant plasmonic superlattice sheets. This bottom-up method involves soft ligandbalanced crystallization of AuNPHs in conjunction with drying-mediated self-assembly. Such AuNPHs superlattice sheets exhibit macroscopic surface area while maintaining a highly ordered nanoscopic structure. We also demonstrate by both experiment and theoretical simulation that the surface-plasmon-induced hotspots are uniformly distributed across the sheet surface, facilitating its application as flexible surface-enhanced Raman scattering (SERS) sensors for detection of 4-aminothiophenol. The Raman enhancement factor (EF) of this flexible SERS sensor can reach 1.7 × 10 6 with a detection limit reaching the nanomolar scale. Moreover, the Raman signals exhibited high homogeneity across the superlattice sheets with a low relative standard deviation of 4.3%. Such flexible AuNPHs superlattice sheets can be applied as nonconventional SERS platforms with well-defined customizability, suggesting a robust and efficient avenue for real-world applications in high-sensitive inspection of drugs, explosives, and environmental pollutants.

Coating Silver Tree‐like Fractal Structure with Silica Layer for Inhibiting Chemical Reactions of Analytes in Surface‐Enhanced Raman Scattering

“…The value was larger compared to others reported elsewhere because a silica layer exists between metallic surface and p-ATP. [29][30][31] However, the silica layer enables SERS measurements without chemical transformations, which would be applicable to unknown samples in practical uses.…”

Highly Stable Nanoparticle Supercrystals Formed by the Aldol Reaction in Conjunction with Slow Solvent Evaporation

“…It has been reported that the optical properties of plasmonic supercrystals (such as Au NPSCs) can be designed by combined control over the nanoscale (interparticle distance, i.e., volume fraction of plasmonic nanoparticles) and mesoscale structures (supercrystal habit and size). The tailored optical properties of plasmonic NPSCs would allow us to manipulate lights, providing new opportunities in potential applications including solar energy harvesting, optical electronics, molecular sensing, and photocatalysis …”

A Surface Enhanced Raman Scattering (SERS) Sensing Method Enhanced by All-metal Metasurface

“…The electromagnetic field can be controlled by the combination of metasurface design and SPs. Therefore, the method of combining LSPR and SERS based on metal nanostructure will have broad prospects [9]. By designing the nanostructure, the optical response can be optimized effectively, and thus favorable sensing sensitivity can be achieved [10,11].…”