雙界面活性劑系統之金奈米棒的合成與金奈米棒之表面修飾以及再生長銀

Synthesis of Gold Nanorods Using Binary Surfactant System, Surface Modification and Silver-Overgrowth on Gold Nanorods

林士堯(Lin Shih-Yao)

指導教授 ： 陳家俊

國立臺灣師範大學/理學院/化學系/碩士(2018年)

https://doi.org/10.6345/THE.NTNU.DC.031.2018.B05

摘要

使用雙界面活性劑系統合成出不同大小以及長寬比的金奈米棒，探討每個條件對於尺寸的影響，尺寸對於金奈米棒的表面電漿共振現象有何種影響及表面修飾過後的奈米金棒在光譜及電子顯微鏡下會如何改變，並對其表面做官能基修飾或者在表面上沉積銀原子形成金-銀雙金屬結構。由於金奈米棒的各向異性導致其具有不均勻的電磁場強度分佈，金奈米棒的兩端對於訊號(如螢光、拉曼散射光)有明顯增強的效果，因此在兩端接上具有螢光放光的金奈米團簇預期會使螢光強度增強。實驗中，表面的官能基修飾選擇使用含有硫醇基的聚合物，方便之後修飾在金奈米棒的表面，聚合反應則是以N-羧酸酐聚合法，合成出直鏈聚合物。聚合物之末端帶有氨基，能透過EDC/NHS與帶有羧酸的分子進行交聯反應，使其固定在聚合物的末端，達到固定在金奈米棒表面的目的。表面修飾後的金奈米棒可選擇性的在兩端接上物質，探討兩端強電磁場對於物質的螢光訊號影響。此外，在金奈米棒上沉積銀原子形成金-銀雙金屬結構(Au/Ag-Core/Shell) (Au@Ag nanocuboids)，探討其在光譜上的變化，之後透過Galvanic Replacement reaction使用CTAC-Au(III)溶液將銀殼表面部分置換成金殼，形成具有空腔之金棒-金殼結構(gold nanorattles)，這樣的結構在空腔內也具有很強的電磁場分佈，期望能在空腔的部分載入螢光物質，預測會有更高的訊號增強。

關鍵字

金奈米棒 ； 表面電漿共振 ； 表面修飾 ； 金奈米團簇 ； 金-銀雙金屬結構 ； 金屬螢光增強

並列摘要

We discuss the synthesis of gold nanorods(AuNRs) using a binary surfactant system. The size and the aspect ratios of AuNRs with tunable longitudinal surface plasmon resonance can be achieved by altering the synthesis conditions of the
seed-mediated growth method. It’s important for investigating the effect of each condition and the growth process of AuNRs. Due to the anisotropy of AuNRs result in a non-uniform distribution of the electromagnetic field. There is a significantly enhancement upon the optical signals (such as fluorescence or Raman scattering light) at the ends of AuNRs. It’s predicable that the fluorescence signals will be enhanced if the fluorescent dye molecules or fluorescent light-emitting gold nanoclusters(AuNCs) placed at the ends of AuNRs. We functionalize the ends of AuNRs with amine-functional thiolate polymer because of carboxyl group contained fluorescent dye molecules and mercaptosuccinic acid-stablilized AuNCs. Linking up amine group with carboxyl group is achievable through EDC/NHS crosslinking. We also present that the deposition of silver atom on the surface of AuNRs forming the cuboidal Au/Ag-core/shell structure (Au@Ag nanocuboids) and then discuss the changing of morphology and the different of absorption spectra. Au@Ag nanocuboids can be further etched by Au(III)-CTAC solution results in a cavity Au rod/Au shell structure (gold nanorattles). It can be predicted if loading the fluorescence materials leads to high electric-field enhancement inside the cavity.

並列關鍵字

gold nanorods ； Localized Surface Plasmin Resonance ； gold nanoclusters ； Au/Ag binary metal structure ； surface modification ； metal-enhanced fluorescence ； Galvanic Replacement reaction

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