Laser Deposition of SERS-Active Silver Nanostructures on Silicon Surface

Binary Thiol-Capped Gold Nanoparticle Monolayer Films for Quantitative Surface-Enhanced Raman Scattering Analysis

“…In particular, nanoscale junctions between metal nanoparticles, known as “hotspots”, can dramatically enhance local electromagnetic (EM) fields and thus allow ultrasensitive analysis of molecules located inside the hotspots . However, owing to the near-field nature of SERS phenomenon, the enhancement factors (EFs) in the hotspots are highly sensitive to the size, shape, and spacing of the nanoparticles, − as well as local dielectric environments. − As a result, quantitative SERS analysis has been a major challenge in practical applications because of the difficulty in obtaining uniform and reproducible SERS substrates. , Recently, self-assembled nanoparticle monolayers with high-density and uniform hotspots have attracted great interests as SERS substrates. ,− In particular, self-assembled gold nanoparticle (AuNP) monolayers offer the advantages of high plasmonic activity in the visible to near-infrared regions, chemical stability, well-tunable nanostructures, , and simplicity and scalability of their preparation. − However, the EFs of self-assembled AuNP monolayers can still vary by orders of magnitude due to sample and instrument variations, such as laser power, integration time, and polarization of incident light …”