Abstract In this work, various geometries of Au nanocrystals with sharp tips including decahedra, concave star, and spindle were synthesized through Ag underpotential deposition-dominated growth approach based on utilizing a novel type of Au nanoseed (i.e., pentatwinned Au nanospheres). These as-prepared Au nanocrystals exhibited a broad localized surface plasmon resonance (LSPR) tunability from visible to near-infrared region. Furthermore, we fabricated the monolayer film based on Au nanocrystals with different morphologies through liquid/liquid interface self-assembly technique, which displayed strong shape-dependent surface enhanced Raman scatting (SERS) performance. More significantly, concave star-shaped Au nanocrystals with ten sharp tips endowed them with 12-fold higher SERS enhancements than Au nanospheres, which was in line with the simulation results by finite difference time domain (FDTD) method. Our study provides a novel route for fabrication of Au nanocrystals with diversified structures, and the efficient SERS substrates have great prospect for the applications in ultrasensitive chemical and biological sensing.

中文翻译：

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凹星形金纳米晶的自组装单层膜作为高效 SERS 衬底

摘要 在这项工作中，基于一种新型金纳米种子（即五联金纳米球），通过银欠电位沉积主导生长方法合成了各种几何形状的具有尖尖的金纳米晶体，包括十面体、凹星形和纺锤体。这些制备的 Au 纳米晶体表现出从可见光到近红外区域的广泛局域表面等离子体共振 (LSPR) 可调性。此外，我们通过液/液界面自组装技术制备了基于不同形貌的金纳米晶的单层薄膜，该薄膜显示出强大的形状相关表面增强拉曼散射（SERS）性能。更重要的是，具有十个尖端的凹星形 Au 纳米晶体赋予它们比 Au 纳米球高 12 倍的 SERS 增强，这与有限差分时域（FDTD）方法的仿真结果一致。我们的研究为制备具有多样化结构的Au纳米晶体提供了一条新途径，高效的SERS基底在超灵敏化学和生物传感中具有广阔的应用前景。