“热点”富集金纳米颗粒的制备及拉曼应用研究

Research on the Preparation of Gold Nanoparticles Enriched with “Hot Spots” and Their Raman Applications

摘要: 具有高光–热利用效率的三维等离子体纳米结构在各个领域展现出工业化前景，在光–热转换、太阳能俘获等方面成为研究的热点。本文提出了一种简单的化学合成方法来制备“热点”富集金纳米颗粒，并采用电泳沉积方法来组装大面积的“热点”富集金纳米颗粒薄膜。通过数值模拟和实验，研究了“热点”富集金纳米颗粒薄膜的表面增强拉曼散射(SERS)测试。结果揭示了“热点”富集金纳米颗粒薄膜的局域电场光增强和光–热转换的物理过程。结果表明，借助“热点”富集金纳米颗粒薄膜高效的光学俘获特性和超亲水表面特性，使其在拉曼信号增强方面呈现显著效果。其中，基于金纳米球颗粒和“热点”富集金纳米颗粒的SERS基底，对R6G分子的极限灵敏度分别达到10⁻¹⁰ M和10⁻¹² M。因此，“热点”富集金纳米颗粒薄膜在有机分子的拉曼痕量检测领域具有极强的竞争力。

Abstract: Three-dimensional plasmonic nanostructures with high light-heat utilization efficiency have shown industrialization prospects in various fields and have become a research hotspot in aspects such as light-heat conversion and solar energy capture. This paper proposes a simple chemical synthesis method to prepare “hotspot”-enriched gold nanoparticles and uses electrophoretic deposition to assemble large-area “hotspot”-enriched gold nanoparticle films. Through numerical simulation and experiments, the surface-enhanced Raman scattering (SERS) testing of the “hotspot”-enriched gold nanoparticle films was studied. The results reveal the physical processes of local electric field enhancement and light-heat conversion of the “hotspot”-enriched gold nanoparticle films. The results show that, with the help of the efficient optical trapping characteristics and superhydrophilic surface characteristics of the “hotspot”-enriched gold nanoparticle films, they exhibit remarkable effects in terms of Raman signal enhancement. Among them, based on gold nanosphere particles and “hotspot”-enriched gold nanoparticles, the limit sensitivities of the SERS substrates for R6G molecules reach 10⁻¹⁰ M and 10⁻¹² M, respectively. Therefore, the “hotspot”-enriched gold nanoparticle films have strong competitiveness in the field of Raman trace detection of organic molecules.