标记免疫双组分的SERS检测研究

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

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）.

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.