Ao Limei, Gao Feng, Pan Bifeng, He Rong, Cui Daxiang
Department of Bio-Nano Science and Engineering, National Key Laboratory of Nano/Micro Fabrication Technology, Institute of Micro and Nano Science and Technology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China.
Anal Chem. 2006 Feb 15;78(4):1104-6. doi: 10.1021/ac051323m.
A unique, sensitive, and highly specific fluoroimmunoassay system for antigen detection using gold and magnetic nanoparticles has been developed. The assay is based on the fluorescence quenching of fluorescein isothiocyanate caused by gold nanoparticles coated with monoclonal antibody. To demonstrate its analytical capabilities, the magnetic nanoparticles were coated with anti-alpha-fetoprotein polyclonal antibodies, which specifically bound with alpha-fetoprotein. Gold nanoparticles coated with anti-alpha-fetoprotein monoclonal antibodies could sandwich the alpha-fetoprotein captured by the magnetic nanoparticle probes. The sandwich-type immunocomplex was formed on the surface of magnetic nanoparticles and could be separated by a magnetic field. The supernatant liquid, which contained the unbound gold nanoparticle probes, was used to quench the fluorescence, and the fluorescence intensity of fluorescein isothiocyanate at 516 nm was proportional to the alpha-fetoprotein concentration. The result showed that the limit of detection of alpha-fetoprotein was 0.17 nM. This new system can be extended to detect target molecules with matched antibodies and has broad potential applications in immunoassay and disease diagnosis.
已开发出一种独特、灵敏且高度特异的用于抗原检测的荧光免疫分析系统，该系统使用金纳米颗粒和磁性纳米颗粒。该分析基于用单克隆抗体包被的金纳米颗粒导致异硫氰酸荧光素的荧光猝灭。为证明其分析能力，用抗甲胎蛋白多克隆抗体包被磁性纳米颗粒，其与甲胎蛋白特异性结合。用抗甲胎蛋白单克隆抗体包被的金纳米颗粒可夹在磁性纳米颗粒探针捕获的甲胎蛋白之间。夹心型免疫复合物在磁性纳米颗粒表面形成，可通过磁场分离。含有未结合金纳米颗粒探针的上清液用于猝灭荧光，516nm处异硫氰酸荧光素的荧光强度与甲胎蛋白浓度成正比。结果表明，甲胎蛋白的检测限为0.17nM。这种新系统可扩展用于检测与匹配抗体结合的靶分子，在免疫分析和疾病诊断中具有广泛的潜在应用。
