Automated chemiluminescent dual-analyte immunoassay based on resolved immunosensing channels

A novel system of series-wound immunosensing channels (SWIC) was proposed for automated chemiluminescent (CL) dual-analyte immunoassay by immobilizing respectively different capture antibodies on the inner walls of series-wound glass channels. This system could use a single enzyme as label to perform multiplex immunoassay in one fluid way. Using α-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as model analytes, the mixture including AFP, horseradish peroxidase (HRP)-labeled anti-AFP antibody, CEA and HRP-labeled anti-CEA antibody was introduced into the SWIC for carrying out the on-line incubation. Upon injection of CL substrate the CL signals from the two immunosensing channels were conveniently resolved and near-simultaneously collected with the aid of optical shutter. AFP and CEA could be rapidly assayed in the ranges of 1.0-100 and 1.0-80 ng/ml with detection limits of 0.41 and 0.39 ng/ml, respectively. The assay results of clinical serum samples were in an acceptable agreement with the reference values. This designed flow-through immunosensing system based on SWIC provided an automated, reusable, simple, sensitive and low-cost approach for multianalyte immunoassay.     

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).