A Nanostructured SERS Switch Based on Molecular Beacon-Controlled Assembly of Gold Nanoparticles

In this paper, highly purified and stable gold nanoparticle (AuNP) dimers connected at the two ends of DNA linkage were prepared by a versatile method. A nanostructured, surface-enhanced Raman scattering (SERS) switching sensor system was fabricated based on the controlled organization of gold nanoparticles (AuNPs) by a DNA nanomachine through the controlled formation/deformation of SERS "hotspots". This strategy not only opens opportunities in the precise engineering of gap distances in gold-gold nanostructures in a highly controllable and reproducible fashion, but also provides a unique ability to research the origin of SERS and sequence-specific DNA detection.