近年來，非破壞性表面增強拉曼散射光譜已被廣泛的運用在諸多領上，如生物體內顯影、生醫檢測、重金屬與農藥殘留檢測以及反應即時監等。因為獨特的局部表面電漿共振效應，使得金屬奈米粒子被廣泛地運用在表面增強拉曼散射的技術上。金、銀核殼奈米粒子的局部表面電漿共振效應會隨著結構、核殼的成分比例以及形狀等因素改變而變化，其結構在電漿共振相關領域上已受到廣泛的注目。近年已有數篇文獻證實，金銀的核殼奈米粒子能夠得到比單一金屬奈米粒子（金或銀）更出色的拉曼增強表現。為了得到這個獨特的料，晶種法是最常被使用的合成手段，然而這個方法非常的耗時，製程也相對雜。
然而，用於痕量檢測的表面增強拉曼散射（SERS）基板設計中的重要但經常被忽略的考慮因素之一是樣品收集的效率。 基於剛性基材（如矽，氧化鋁和玻璃）的常規設計會與被調查表面發生共形接觸，從而導致樣品採集效率低下。 因此，我們想展示一種基於吸附有等離激元金屬納米粒子的普通濾紙的新型SERS基質，它可以與現實世界的表面進行保形接觸，從而與傳統的剛性基質相比，大大提高了樣品收集效率。
本論文的研究目的在於開發一步驟製程奈米粒子的技術(包括單銀奈米粒子和金核銀殼的奈米粒子)並負載於可拋棄式紙基材，將它用在表面增強拉曼光譜的應用上。在研究中，我們透過大氣常壓微電漿與液相反應進行金屬奈米粒子的合成。微電漿是一種氣體放電型態，其定義為至少幾何維度小於一毫米的電漿。此外微電漿可與水溶液電極一同作用。透過微電漿內形成的能量物種可以在不含化學還原劑的水溶液環境下驅動電化學反應以及匯聚粒子。根據實驗結果，大氣常壓微電漿反應器可以在數分鐘內快速地合成金屬奈米粒子，我們將此方法進一步延伸到複合兩種金屬的反應。最後，藉由一步驟大氣常壓微電漿與液相反應，在相對短時間內便能取得金核銀殼奈米粒子之紙基材。經過高解析電子顯微鏡分析，發現透過大氣常壓微電漿進行合成，可以得到均勻貼附在金表面的銀奈米殼層。實驗中所合成的材料會經過紫外光光譜、穿透式電子顯微鏡、掃描式電子顯微鏡、拉曼光譜以及 X 光繞射分析儀。
進一步將所得的材料進行有系統的表面增強拉曼散射研究，我們以羅丹明6G作為偵測分子，使用的雷射光波長為532 nm。在我們的系統下發現金核銀殼雙金屬奈米粒子的增強表現在特定的比例下最為顯著相較金、銀奈米粒子也有較強的表面增強拉曼訊號強度。在極限濃度偵測的實驗上，羅丹明6G分子 的偵測極限達到10-15莫爾濃度。與其他使用相同結構的文獻相比，我們的材料具有相對較出色的偵測表現更低的偵測極限且在材料製備也相對的有效率短時間，達到一步驟結合製程奈米金屬與負載奈米金屬於基材的技術。另外，我們也提出立用微電漿系統輔助可能雙殼核奈米金屬的機制
最後，為了測試我們材料作為生物基材的可行性，我們針對生物分子「葉酸」進行偵測，葉酸是人體內重要的維他命 B ，醫學研究指出當葉酸分子低於 10-8 莫爾濃度，身體可能會有健康上的 疑慮。將葉酸做為探測分子進行表面增強拉曼散射的研究，發現當金核銀殼雙金屬奈米粒子作為基材，對葉酸分子的偵測極限可以達到 10-10 莫爾濃度，低於醫學研究所要求的檢測濃度，顯示出此材料在生醫分子感測的應用上極具潛力。

Surface enhanced Raman scattering (SERS) is a non-destructive technology for various applications including in vivo imaging, bio-sensing, heavy metal or pesticide residues and in situ monitoring. Metal nanoparticles have been widely investigated in SERS applications due to their unique localized surface plasmonic resonance (LSPR). Au/Ag core-shell nanoparticles (Au@Ag NPs) allow tuning their LSPR by varying the size and shape of the core or thickness of the shell and even producing stronger SERS activity in comparison with monometallic Au and Ag NPs. Therefore, they have attracted a lot of attention recently. To synthesis this attracted material, seed-mediated growth is the most widely used method. However, this conventional approach is usually time-consuming and laborious.
However, one of the important but often overlooked considerations in the design of surface-enhanced Raman scattering (SERS) substrates for trace detection is the efficiency of sample collection. Conventional designs based on rigid substrates such as silicon, alumina, and glass resist conformal contact with the surface under investigation, making the sample collection inefficient. So we want to demonstrated the demonstrate a novel SERS substrate based on common filter paper adsorbed with plasmonic metal nanoparticles, which allows conformal contact with real-world surfaces, thus dramatically enhancing the sample collection efficiency compared to conventional rigid substrates.
In our report, we present a facile synthesis of Ag nanoparticles and Au@Ag bimetallic nanoparticles deposited on the filter paper using a novel atmospheric-pressure microplasma-assisted electrochemistry. Microplasmas are defined as gaseous discharges formed in electrode geometries where at least one dimension is less than 1mm. Due to surface volume change, microplasmas can be operated stably with an aqueous solution as an electrode at atmospheric pressure. Energetic species formed in the microplasma is capable of initiating electrochemical reactions and nucleating particles in solution without chemical reducing agents. In our results, we demonstrated one-step fabrication metal nanoparticles / filter paper. That is meaning we can synthesis MNP and deposit that on the filter paper in the same time. Another we synthesized Au@Ag core-shell bimetallic NPs in a minute time scale microplasma system. In comparison to seed-mediated growth, microplasma system not only can constitute Au@Ag NPs but also make the Ag shell forming on the Au surface more homogeneous instead of randomly attached Ag atoms. As-produced samples were characterized by UV-vis, TEM, XRD, and Raman.
We further systematic studied the SERS performance of Au@Ag NP /filter paper and Au@Ag core-shell bimetallic nanostructure showed superior enhancement of SERS activity than Au, Ag NPs. The limit of detection of R6G molecules can be as low as 1 fM and high enhancement factor of 5 x 1013. It allows the SERS detection at single molecule level in R6G analysis. We further systematically studied to propose mechanism of Au@Ag NPs formation in one-step microplasma process. In addition, for the purpose of bio-molecule sensing, we demonstrate the feasibility of using Au@Ag NPs as the SERS substrate for detecting the folic acid (FA) molecule. The result show that the limit of detection of FA can achieve 1 femimolar-level detection.

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