Highly tunable plasmonic nanoprobes and their couplings

" Synthesizing and controlling plasmonic nanostructures such as Au and Ag nanoparticles (AuNPs and AgNPs) with high precision and high yield are of paramount importance in optics, nanoscience and materials science. It is particularly important to generate and control ~1-nm plasmonic gap because plasmonic gaps of ~1 nm or less can generate exponentially stronger plasmonic coupling signals than >1-nm plasmonic gap. Among many examples of the use of plasmonic nanogap, surface-enhanced Raman scattering(SERS)-based signal amplification and bio-detection methods using SERS-active plasmonic nanoparticles (NPs) have been drawing significant interest, and it has been known that SERS effect is intense when Raman dyes are located within <1-nm inter-particle junction. However, these SERS-active NPs and SERS-active NP-based detection strategies have not been practically useful because there is no straightforward method to synthesize desired SERS-active nanostructures in a high yield, great precision and nm-level controllability. For these reasons, reproducible and quantitative SERS signal generation from SERS probes is very challenging and the widespread and practical use of SERS nanoprobes has been largely limited.


Here, I will describe DNA-based synthetic strategies to build up new types of plasmonic nanogap Au/Ag structures with high structural controllability. The use of these plasmonic nanostructures including anisotropic nanostructures as excellent optical signal enhancement platforms to address the above-mentioned issues in"