标记免疫双组分的SERS检测研究

以金膜为免疫检测的基底, 采用自组装技术(Self-assembled monolayer, SAM)将ω-巯基十六酸(16-MHA)修饰于金膜后与抗体结合成固相抗体, 在此基础上组装“固相抗体-待测抗原-标记免疫金溶胶”三明治复合体系. 采用不同标记分子苯硫酚(Thiophenol)和4,4'-联吡啶(4,4'-Bipyridine)分别标记不同的免疫金溶胶, 利用表面增强拉曼光谱(SERS)谱峰较窄且具有较强的分辨率及高灵敏度的特点, 通过对两种标记分子特征谱峰的判断识别所加入的两种抗原. 通过选择合适的标记分子和一定尺度的免疫溶胶, 标记免疫SERS检测的检测限可达到飞克级(1—100 fg/mL).

Labeled Immunoassay of Dual-Analyte Utilizing Surface-Enhanced Raman Spectroscopy

Au film which was used as immunoassay substrate was modified by 16-mercaptohexadecanoic acid(16-MHA) via self-assembled monolayer(SAM) technology. A sandwich assay which contains captured antibodies, antigens and labeled immuno-colloids was formed. Two different Raman reporter molecules(4,4'-bipyridine and thiophenol), which served as respective labels for each type of antibodies, were selected. SERS has the advantage of a small line width of Raman bands and high sensibility. The presence of dual-analyte was established by distinguishing the corresponding labeled reporter's Raman spectrum. By chosing suitable Raman reporter molecules and immuno-colloids of certain size, detection limit ranges from 1 to 100 fg/mL were achieved.