Enhancement of assay sensitivity by using magnetic nano-particles and microfluidic chip on C-reactive protein

• Main Authors: Pei-Shin Tsai, 蔡珮欣
• Other Authors: Sien Chi
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/01471862316765258766

碩士 === 國立交通大學 === 光電工程系所 === 93 === 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.