Abstract The presence of sharp tips and edges of gold nanobipyramids (GNBPs) lead to strong local electromagnetic field enhancement. Herein for the first time we present a study on efficacy of additive acid on the formation of GNBPs. The effect of additive acid type and its concentration in growth solution were investigated to obtain various yield and aspect ratio of GNBPs. Morphological characterization shows the nanoseeds that were grown in growth solution prepared using HCl, H2SO4, and HF at concentration from 0 to 1 mL produced GNBPs with yield ranges from 5.21 ± 0.44 to 91.46 ± 3.32% and aspect ratio from 2.00 ± 0.02 to 2.76 ± 0.05. The optical response of GNBPs exhibit dual plasmon band at wavelength around 550 nm–570 nm, corresponding to transverse surface plasmon resonance (t-SPR) and at wavelength around 700 nm–800 nm, corresponding to longitudinal surface plasmon resonance (l-SPR). The presented approach may be used to produce tunable morphological GNBPs nanostructures which potentially used in sensors, SERS, catalysis, and photonics.

中文翻译：

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添加酸对金纳米双锥体种子生长的影响

摘要 金纳米双锥体 (GNBPs) 尖尖和边缘的存在导致强烈的局部电磁场增强。在此，我们首次提出了关于添加酸对 GNBP 形成的功效的研究。研究了添加酸类型及其在生长溶液中的浓度的影响，以获得各种产率和纵横比的 GNBP。形态表征显示，在使用 HCl、H2SO4 和 HF 制备的生长溶液中生长的纳米种子，浓度为 0 至 1 mL，产生的 GNBPs 的产量范围为 5.21 ± 0.44 至 91.46 ± 3.32%，纵横比为 2.00 ± 0.02 至 2.76 ± 0.05。GNBPs 的光学响应在波长约 550 nm–570 nm 处表现出双等离子体带，对应于横向表面等离子体共振 (t-SPR) 和波长约 700 nm–800 nm，对应于纵向表面等离子体共振 (l-SPR)。所提出的方法可用于生产可调谐形态的 GNBP 纳米结构，这些纳米结构可能用于传感器、SERS、催化和光子学。