多功能奈米粒子與其在生物偵測上的應用

Abstract

奈米粒子標籤已經被證實在生物檢測領域具有很好的量測效果，因為訊號因子能夠有效提供穩定的表面增強拉曼散射 (SERS) 訊號，並且具有再現性及很高的靈敏度。我們發展了一套技術來利用 SERS 量測 EV71 的訊號。透過改變訊號因子以及調整外殼厚度及材料之後，我們得到最強的訊號為 10nm 厚度的金殼構成的奈米粒子標籤。接著在殼上修飾抗體，用來偵測 EV71 抗原。我們建立了 SERS 強度對抗原的檢量線，得到的結果是 EV71 的偵測極限為 1.33 μg/mL。我們認為這一項可以在低濃度情況下亦具有很好靈敏度的 EV71 偵測實驗可以在未來應用於實質的生物檢測當中。我們另外合成出奈米攪拌子，用意是能夠均勻地分散於溶液之中，藉由在溶液中能夠旋轉使得抗原的偵測更加快速。我們創造出各種不同粒徑的攪拌子，並且能夠從顯微鏡下方觀察到攪拌子隨著磁場變化而旋轉。在鍍金攪拌子上的訊號因子能夠提供很好的SERS訊號，因此我們認為攪拌子具有潛力協助往後在SERS領域中的快速量測。

The first part of thesis is focused on the preparation of gold nanosphere particle. Nanosphere particle SERS tags with core-molecular-shell (CMS) structure that embedded Raman reporter in SERS tags to circumvent disturbance of non-targeted molecules has been found to be an effective tool in biological sensing. Herein, we report our results of using CMS SERS tags for the detection of Enterovirus 71 (EV71). We first optimized the CMS SERS tags with various conditions including materials of CMS, thickness of CMS and reaction time. Our results show that 10 nm thickness of gold shell of SERS tags offers the highest SERS signals. EV71 antibody conjugated CMS SERS tags is used for detection of EV71 antigen. The correlation between SERS intensity of SERS tags and concentration of EV71 antigen is established. The detection limit is found to be 1.33 g/mL. In the second part of the thesis, we attempted to develop a SERS-active nano-sized magnetic stir bars which can potentially accelerate the process of antigen detection. We demonstrated that various sizes of stir bars can be prepared. The fast response of nano-sized stir bars to magnetic stirrer was validated under microscope. Results demonstrate that strong SERS activity can be generated by this magnetic response platform. This study provides a novel strategy that can be possibly used for rapid detection of SERS.