應用磁性奈米微粒及微流晶片作血漿C-反應蛋白的微量檢測

Abstract

C反應蛋白(簡稱CRP)是一種發炎反應期肝臟製造的敏感性產 物．最近研究指出CRP在心臟病或癌症病人血漿中含量較高，可被 視為是一項冠狀動脈疾病的危險因子．因此，在臨床診斷化驗室裡 微量CRP靈敏及快速之分析是急切地需要的． 本篇論文中利用抗CRP的抗體結合磁性奈米微粒做為固定相取 代傳統酵素連結免疫分析法之微滴定量孔盤，結果証實偵測極限可由6.1 μg/ml，改進至0.1 μg/ml．此引人著目的改進明顯是藉由奈米微粒增加了單位體積之檢測表面積比，不只增加了偵測極限，也簡化了分析程序．同樣地，應用相近的程序但不需加入己結合酵素的抗CRP抗體，於超導量子干涉元件量測飽和磁化率可達到更低的偵測極限至13 ng/ml． 除此之外，雷射激發螢光之微流晶片元件也適合作CRP檢測． 一小段已結合了標記有螢光染劑Cy5之二次抗體的抗CRP抗體混合CRP，注入T形設計的微管道中，實驗結果指出當CRP存在下會多出一個波峰，而此波峰的面積正比於CRP含量．此兩種CRP的分析方法未來充分運用達最佳化後將會是非常具有前瞻性的．

C-reactive protein (CRP) is an acute phase reactant which is produced by liver during the episode of acute inflammation. Recent studies indicated that CRP may also be elevated in heart attack or cancer patients and can be considered as a positive risk factor for coronary artery disease. A sensitive and fast assay for detecting micro-amount of CRP is urgently required by clinical diagnostic laboratories. In this report, magnetic nano-particles were labeled with anti-CRP antibody as a solid phase to substitute the microtiter plate of conventional ELISA assay. The results showed that the limit of detection (LOD) could be improved from 6.1 to 0.1 μg/ml. This dramatic improvement is obviously due to increasing the surface area/volume ratio by the nano-particles. This new method not only improved the LOD but also simplified the assay procedure. The same procedure except without second antibody-HRP was added, the magnetic remenance was measured by SQUID, the results showed an even more lower LOD (13 ng/ml). In addition, a laser-induced fluorescence microfluidic chip device also adapted for CRP detection. A plug of anti-CRP antibody conjugated second Cy5 labeled antibody mixed CRP was injected into microchannel by T-shape channel design. The results indicated that the extra peak was appeared when CRP was added and the peak area is proportional to the amount of CRP. Both of CRP assay methods are promising for the future application with some more optimization.