Probing Dynamic Generation of Hot-Spots in Self-Assembled Chains of Gold Nanorods by Surface-Enhanced Raman Scattering

Abstract

Further progress in the applications of self-assembled nanostructures critically depends on developing a fundamental understanding of the relation between the properties of nanoparticle ensembles and their time-dependent structural characteristics. Following dynamic generation of hot-spots in the self-assembled chains of gold nanorods, we established a direct correlation between ensemble-averaged surface-enhanced Raman scattering and extinction properties of the chains. Experimental results were supported with comprehensive finite-difference time-domain simulations. The established relationship between the structure of nanorod ensembles and their optical properties provides the basis for creating dynamic, solution-based, plasmonic platforms that can be utilized in applications ranging from sensing to nanoelectronics.

Three-dimensional SERS hot spots for chemical sensing: Towards developing a practical analyzer

“…More hotspots in terms of absolute numbers being available in a 3D space will certainly help to transform SERS into a practical analytical technique. To address the issues on 3D geometry of hotspots, various surfactants, DNA, peptide, DNA origami [10], amphiphilic polymers, or even proteins have been used to construct 'fixed' hotspots on solid substrates by preparing oriented assemblies of functional NPs, such as SHINERS [11], core-shell monomers [12], dimers [13,14], trimers [15], chains [16], arrays [17,18], aggregates [19,20], or even multilevel structures [21,22]. On the other side, 'flexible' designs utilizing electronic, ferroelectric, thermal, mechanical strain, or capillary effects have allowed for the tunability of 3D plasmonic hotspots.…”

“…(Reprinted with permission from[2,3,11,14,16,45,50,68,77,83]) Self-assembling fabrication and characterization of 3D plasmonic structures. (A) Top, Schematic depicting the self-assembly of polystyrene-stabilized metallic NPs into clusters.…”

Surface-enhanced Raman scattering (SERS)-active gold nanochains for multiplex detection and photodynamic therapy of cancer

“…Recently, various conventional SERS nanoprobes have been developed for biological applications [40][41][42][43]. However, a SERS-active AuNC for cancer multiplex detection and therapy has not been reported.…”

Controlling dynamic SERS hot spots on a monolayer film of Fe3O4@Au nanoparticles by a magnetic field

“…Lee et al detected the SERS effect during the dynamic generation of hot spots in self-assembled chains of Au nanorods. They established a direct correlation between ensemble-averaged SERS and extinction properties of the nanoparticle ensembles [26]. Wang et al developed approaches to accomplish the dynamic assembly of nanostructures for controlling optical, electronic, and magnetic properties [27].…”