Lee Jin-Ho, Kang Da-Yeon, Lee Taek, Kim Sang-Uk, Oh Byung-Keun, Choil Jeong-Woo
Department of Chemical and Biomolecular Engineering,Sogang University, #1 Shin-su, Mapo-gu, Seoul 121-742, Republic of Korea.
J Nanosci Nanotechnol. 2009 Dec;9(12):7155-60. doi: 10.1166/jnn.2009.1613.
Numerous studies have indentified that beta-amyloid (1-40) in cerebrospinal fluid as a potential biomarker for Alzheimer's disease. In order for early detection of the Alzheimer's disease, an ultrasensitive diagnostic tool is required. In this study, an ultrasensitive surface plasmon resonance (SPR) based immunosensor for beta3-amyloid (1-40) was developed and its signal enhanced (1-40) with a gold (Au) nanoparticle-antibody complex. Antibodies to beta3-amyloid (1-40) were immobilized on the Au surface leading to a highly efficient immunoreaction due to the fact the paratope of the antibody faced in the opposite direction to the solid surface. The surface morphology of the bio-surface was investigated by using scanning tunneling microscopy (STM). The binding process of antibody fragments to the Au surface, target analytes, and Au nanoparticle-antibody complexes were monitored using SPR. The plot of SPR angle difference versus beta3-amyloid (1-40) concentration shows a linear correlation over a concentration range of nine orders of magnitude, having a detetion limit up to 1 fg/ml.
众多研究已确定脑脊液中的β-淀粉样蛋白（1-40）是阿尔茨海默病的一种潜在生物标志物。为了早期检测阿尔茨海默病，需要一种超灵敏的诊断工具。在本研究中，开发了一种基于表面等离子体共振（SPR）的超灵敏β-淀粉样蛋白（1-40）免疫传感器，并用金（Au）纳米颗粒-抗体复合物增强其信号。β-淀粉样蛋白（1-40）抗体固定在金表面，由于抗体的互补位面向与固体表面相反的方向，从而导致高效的免疫反应。使用扫描隧道显微镜（STM）研究了生物表面的形态。使用SPR监测抗体片段与金表面、目标分析物以及金纳米颗粒-抗体复合物的结合过程。SPR角度差与β-淀粉样蛋白（1-40）浓度的关系图在九个数量级的浓度范围内呈线性相关，检测限高达1 fg/ml。
