Gold Nanoparticles Immobilized on Honeycomb-like Polymeric Films for Surface-Enhanced Raman Scattering (SERS) Detections

• Main Authors: Chia-Yen Chiang, 江佳晏
• Other Authors: Ru-Jong Jeng
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/f2cb94

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 105 === Novel surface-enhanced Raman scattering (SERS) substrates with three-dimensional (3D) porous structures have been developed for effectively improving the sensitivity and reproducibility of SERS, which can rapidly detect small molecules. Periodical arrays of the honeycomb-like substrates were fabricated by self-assembling polyurethane-co-azetidine-2,4-dione (PU-PAZ) polymers. PU-PAZ comprising amphiphilic dendrons could stabilize the interfaces between the water droplets and polymer solution, and then organize into regular porous structures through the breath figure method. Subsequently, SERS substrates were fabricated by immobilizing gold nanoparticles (AuNPs) onto the polymer films with various 3D honeycomb-like porous structures, controlled by different PU-PAZ concentrations and relative humidities. Results show that surface enhancement factors of honeycomb-like substrates as large as 106 are much higher than that of flat-film substrates (control group) due to enormous accumulation of hot-spots resonance effects in the 3D porous structure as verified through Raman mapping at various positions of the z-axis. Furthermore, the particle size effects were evaluated by immobilized different sizes of AuNPs on the honeycomb-like substrates, indicating larger AuNPs could induce more pronounced hot-spots effects as verified by the broad scattering peak of aggregating AuNPs. The generation of hot-spots resonance to enhance Raman intensity is strongly dependent on the diameter of AuNPs, the pore sizes and distributions of the 3D honeycomb-like porous substrates. Such substrates are ready for label-free and rapid SERS detection. Keywords：surface-enhanced Raman scattering (SERS); breath figure; honeycomb-like polymeric films; gold nanoparticles; hot-spots resonance effects.