Detection of trace antigens in body fluid using ultrasensitive immunoassay by laser induced photothermal spectroscopy and its application to the forensic medical tests

我们开发了几种新的免疫分析的基础上高度敏感的检测光热转换系统，在传统的吸收分光光度检测器。它们是使用光热偏转光谱的免疫结合测定法、使用激光诱导的毛细管振动（CVL）的毛细管区带电泳（CZE）和光热显微镜。这些方法的新特点是采用激光光热法可行的胶体金作为标记材料，利用这些新发展的免疫分析方法，可以检测和定量人血清中的微量抗原，即癌胚抗原、IgE、刘易斯抗原。我们还可以检测人绒毛膜促性腺激素，以及一些药物，尿中的甲基苯丙胺和肾小管上皮细胞中的抗生素。这些检测方法灵敏度高，易于检测样品中的痕量物质。因此，这些新的免疫检测方法适用于法医学检验和/或临床诊断。

We developed several new immunoassays based on highly sensitive detection by a photo-thermal conversion system, in place of conventional absorption spectrophotometric detectors. They are an immunobinding assay using photothermal deflection spectroscopy, a capillary zone electrophoresis (CZE) which uses capillary vibration induced by laser (CVL) and a photothermal microscopy. The new feature of these methods is the use of colloidal gold which is feasible to laser photothermal method as a labeling material.Using these newly developed immunoassay methods, we could detect and quantitate trace antigens in human sera, i.e.carcinoembryonic antigen, IgE,Lewis antigens. We could also detect human chorionic gonadotropin, and some drugs, methamphetamine in urine and antibiotics in a epithelial cell of renal tubules.These assay methods are sensitive and easy enough to detect trace substances in samples. Therefore, these new immunoassays are applicable to forensic medical test and/or clinical diagnosis.