摘要
探索一种可以高密度固定抗原的新方法,并用于研究多层纳米金修饰金膜表面包被抗原的新型人绒毛膜促性腺激素(HCG)表面等离子体共振(SPR)传感器。3-巯丙基甲基二甲氧基硅烷(MPTMS)与纳米金粒子(AuNPs)可通过Au-S键在传感器金膜表面交替组装形成三维网络,膜表面空间结构中的纳米金经静电作用可吸附大量的小分子抗原HCG,从而获得多层膜修饰的HCG免疫传感器用于检测抗原抗体结合反应。用所构建的HCG传感器,直接检测不同浓度的anti-HCG抗体有良好的线性关系,且修饰两层胶体金膜比修饰一层时抗体响应的共振峰移动幅度提高了1.8倍,检测下限降低至1.5μg/mL。间接法测定了不同浓度的HCG,其浓度与SPR共振峰的位移呈负相关。实验通过修饰两层胶体金膜大大提高了金膜表面固定抗原的量,提高了检测抗体的灵敏度,并且进而用竞争法可检测HCG抗原而不需要用第二抗体进行信号放大。有望用于临床实验诊断。
To explore a new method of immobilizing human chorionic gonadotropin （HCG） antigen on gold surface with high density and develop a new type of surface plasmon resonance （SPR） - based immunoassay sensor modified with muhilayer gold nanoparticles coated HCG antigen. Multilayer gold nanoparticles were assembled through Au-S binding on the gold surface to form a 3D-network structure, which can immobilize HCG antigen efficiently by electrostatic adsorption. Different concentration of anti-HCG antibody and HCG were detected by SPR system. The SPR signal shift was linearly related to the concentration of anti-HCG antibody. The SPR resonance wavelength shifted produced by two layers of gold nanoparticles was 1.8 times as a layer one after reaction with anti-HCG antibody. The detection limit was down to 1.5 ug/ml. The HCG antigen has been tested using inhibition assay and the SPR signal shift was negatively related to the HCG concentration. Multilayer assembly is an efficient method to immobilize much more HCG antigen to improve the detecting sensitivity. The concentration of anti-HCG antibody could be detected directly, and HCG antigen could be detected indirectly by this biosensor chip, which was simple, dynamic and did not need secondary antibody. The method was expected to be applied in clinical diagnostics.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2012年第5期748-754,共7页
Chinese Journal of Biomedical Engineering
