以化學法製備銅奈米薄膜及其螢光增強特性分析
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2018
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Abstract
金屬奈米粒子具有獨特的螢光增強特性，當螢光物質與金屬之間隔有一定距離時，螢光物質受到金屬奈米粒子電場影響，螢光物質會有較多的電子躍遷至激發態，之後回到基態的電子數也增多，進一步增強其放光量，此現象稱為金屬螢光增強(Metal Enhanced Fluorescence , MEF)。
此研究是以無電鍍的方式在水溶液中製備出銅薄膜，以乙醛酸(Glyoxylic acid solution)做為還原劑，並用硫醇修飾其表面，使銅片表面不易與空氣直接接觸，且在後面步驟中TEOS可以更易修飾上，在過去的文獻中發現，銅的局部表面電漿共振 (Localized Surface Plasmon Resonance , LSPR)未受到太大的重視，因為表面有氧化的問題，因此本實驗為了改善其問題，在銅片表面修飾上二氧化矽，且利用改變銅製備時間的長短，觀察螢光強度對銅厚度的結果，將本材料與對照組相比有明顯的染劑螢光強度增強，由此方法可增加整體的螢光增強極限，當銅片的厚度在100奈米左右時，對Streptavidin-IR800有最大的螢光增強，最大值接近60倍。
Metallic nanoparticles possess specific properties called metal enhanced fluorescence (MEF), which plays a crucial role in this study. The concept of MEF is that there will be more electrons transitioned to the excited state from the ground state when the fluorescent substance and metallic nanoparticles are in a certain distance owing to the electric field effect. In addition, there will be more electrons released back to the ground state, which can enhance the emission of the light. The method of preparing copper films in aqueous solution without plating was investigated in this study. Instead of plating method to generate the copper films, glyoxylic acid solution was used as the reducing agent to reduce the copper surface. After the reducing process, the copper surface was modified by (3-Mercaptopropyl)trimethoxysilane to stably remain the films in reduced state. In previous study, the localized surface plasmon resonance (LSPR) of copper was not emphasized in the research due to the problem of oxidation of the material surface. Therefore, as to improve the previous method, the surface of copper was modified by SiO2. In addition, the method in this study to control the time of preparing copper films was shown to have obviously enhancement of the fluorescence of Streptavidin-IR800 according to its results. This method was investigated to promote the overall limit of the enhancement of fluorescence. The copper films with around 100 nm thickness were reported to have the optimal fluorescence enhancement approximately 60 times compared to the previous method.
Metallic nanoparticles possess specific properties called metal enhanced fluorescence (MEF), which plays a crucial role in this study. The concept of MEF is that there will be more electrons transitioned to the excited state from the ground state when the fluorescent substance and metallic nanoparticles are in a certain distance owing to the electric field effect. In addition, there will be more electrons released back to the ground state, which can enhance the emission of the light. The method of preparing copper films in aqueous solution without plating was investigated in this study. Instead of plating method to generate the copper films, glyoxylic acid solution was used as the reducing agent to reduce the copper surface. After the reducing process, the copper surface was modified by (3-Mercaptopropyl)trimethoxysilane to stably remain the films in reduced state. In previous study, the localized surface plasmon resonance (LSPR) of copper was not emphasized in the research due to the problem of oxidation of the material surface. Therefore, as to improve the previous method, the surface of copper was modified by SiO2. In addition, the method in this study to control the time of preparing copper films was shown to have obviously enhancement of the fluorescence of Streptavidin-IR800 according to its results. This method was investigated to promote the overall limit of the enhancement of fluorescence. The copper films with around 100 nm thickness were reported to have the optimal fluorescence enhancement approximately 60 times compared to the previous method.
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金屬螢光增強, 局部表面電漿共振, 銅奈米顆粒, Metal Enhanced Fluorescence, Localized Surface Plasmon Resonance, Copper nanoparticle