This paper describes a new strategy using oxygen plasma treatment to tune the localized surface plasmon resonance (LSPR) of gold nanorods coated with a mesoporous silica shell (AuNRs@mSiO₂) exposed to mercury (Hg) solution. Dark-field (DF) microscopy and spectroscopy were used to reveal the effects of oxygen plasma treatment on the structural and LSPR spectral changes of single amalgamated AuNRs@mSiO₂. Due to the structural stability provided by the mesoporous silica shell, the amalgamated AuNRs@mSiO₂ exposed to oxygen plasma treatment showed no morphological transformation. Furthermore, real-time monitoring of single AuNRs@mSiO₂ showed slow Hg inward diffusion into AuNR cores in air over a long timeframe (24 h), as revealed by the redshift and linewidth narrowing of the LSPR peak. However, the oxygen plasma treatment resulted in faster inward diffusion of Hg into AuNR cores within 20 min, almost 60 times faster than the amalgamated AuNRs@mSiO₂ untreated with oxygen plasma. Thus, oxygen plasma treatment was further presented as a new effective approach to control the LSPR properties by promoting the inward Hg diffusion in amalgamated AuNRs@mSiO₂ without structural deformation.

中文翻译：

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通过在涂有介孔二氧化硅壳的金纳米棒中通过氧等离子体处理促进向内 Hg 扩散来调节等离子体特性

本文介绍了一种使用氧等离子体处理来调整暴露于汞 (Hg) 溶液的涂有介孔二氧化硅壳 (AuNRs@ m SiO _{2 ) 的金纳米棒的局部表面等离子体共振 (LSPR) 的新策略。}使用暗场 (DF) 显微镜和光谱学来揭示氧等离子体处理对单一融合 AuNRs@ m SiO ₂的结构和 LSPR 光谱变化的影响。由于介孔二氧化硅壳提供的结构稳定性，暴露于氧等离子体处理的合并的AuNRs@ m SiO _{2没有表现出形态转变。}此外，实时监测单个 AuNRs@ m SiO ₂显示在很长一段时间内（24 小时），汞缓慢向内扩散到空气中的 AuNR 核心中，正如 LSPR 峰的红移和线宽变窄所揭示的那样。然而，氧等离子体处理导致 Hg 在 20 分钟内更快地向内扩散到 AuNR 核心中，几乎是未经氧等离子体处理的融合 AuNRs@ m SiO ₂的 60 倍。因此，氧等离子体处理被进一步提出作为一种新的有效方法来控制 LSPR 性能，通过促进汞齐化的 AuNRs@ m SiO ₂向内扩散而不发生结构变形。