Dynamic and Reversible Tuning of Particle‐in‐Bowl Shaped Plasmonic Resonators for Switchable Surface Enhanced Raman Scattering. Issue 4 (19th December 2021) - Deng, Fangfang
Abstract: Plasmonic nanoresonators made of particle‐in‐void have been considered as superior plasmonic cavities for surface enhanced Raman scattering (SERS). However, controlled fabrication of such plasmonic system and its dynamic tuning pose great challenges to traditional fabrication methods. Here, a capillary‐driven self‐assembly is proposed to form gold nanoparticles in bowls (Au NPiBs), which have a nm‐gap filled with temperature‐responsive polymers (poly(N‐isopropylacrylamide)). As such, the plasmonic resonances of the Au NPiB nanostructures can be dynamically and reversibly tuned with the change of temperature due to the thermally induced expansion and contraction of the polymers. The SERS enhancement factor (EF) of such Au NPiB can reach up to 10 6, which is also switchable with temperature. The Au NPiB obtained with scalable and facile self‐assembly approach is more defined and uniform compared to any previously reported NPiB structures, making it an ideal SERS switching device with robust reversibility and reproducibility. Abstract : Thermo‐responsive plasmonic system made of Au nanoparticles in gold bowl (Au NPiB) is fabricated via self‐assembly approach with thermal sensitive polymer poly(N‐isopropylacrylamide) as the spacer. This complex plasmonic system shows reversible and dramatic switch of the plasmon resonances as well as the surface enhanced Raman scattering with superior performances and functionality.