Sensitive detection of CZE and analysis of ultratrace biological substances by laser-induced capillary vibration method.

我们发现了激光诱导毛细振动（CVL）效应。CVL的产生机制是基于光热现象。由样品的斩波光束吸收引起的周期性发热使毛细管像弦振动一样振动。CVL的振幅与样品的吸光度成正比，并且我们已经证明了使用CVL效应的超微量分析。另一方面，毛细管区带电泳（CZE）被各科学技术领域所期待，有望成为一种从pI到nI级的超微量样品的强有力的化学分离技术。然而，CZE抑制其实际应用的一个严重问题是缺乏对毛细管中分离的痕量化学物质的检测方法。在此基础上，本课题的目标是研制出CZE/CVL体系，并证明其具有上级性能、高灵敏度和广泛的应用前景。我们可以完成我们的三年研究计划。主要研究成果如下：1）设计并制作了CZE/CVL实验系统。该体系的灵敏度比传统的吸收检测器至少高出2-3个上级数量级。2）阐明了毛细管中光热现象的产生机理，并获得了灵敏定量检测的最佳检测条件。3）利用该系统分离并定量检测了非衍生化的氨基酸; 4）利用该系统分离并检测了吸附在聚苯乙烯微粒上的痕量免疫球蛋白。通过优化反应条件和检测条件，有望实现亚临界水平的免疫分析。

We have found a laser-induced capillary vibration (CVL) effect. The generation mechanism of CVL is based on photothermal phenomenon. Periodical heat generation caused by chopped beam absorption by the sample made the capillary vibrate like a string vibration. The amplitude of the CVL was proportional to the absorbance of the sample, and we have demonstrated ultra-micro analysis using the CVL effect. Onthe other hand, capillary zone electrophoresis (CZE) is expected from various technology and science fields to be a powerful chemical separation technique for ultra-micro quantity samples from pl to nl level. However, a severe problem with CZE inhibiting its practical uses is the lack of a detection method for trace chemical species separated in the capillary. The we have proposed to apply CVL to a sensitive detector of CZE, and shown promising results.On the basis of this course of study, the present research project aimed to develop CZE/CVL system, and to prove superior properties, ultrahigh sensitivity and wide use, which were expected from the preliminary experiments. We could attain our 3 years research plan. The outline of the results are summarized as follows.1) A trial system of CZE/CVL was designed and produced. The sensitivity of the system was at least 2-3 orders superior to conventional absorption detectors.2) The mechanisms of photothermal phenomena induced in a capillary were clarified, and an optimal detection conditions for sensitive and quantitative detection were obtained. These conditions were useful for design of a practical system.3) Non-derivatized amino acids in amol levels were separated and quantitatively detected by this system.4) Trace immunoglobulins in amol levels adsorbed on polystirene microparticles were separated and detected. By optimizing the reaction and detection conditions, sub-amol levels immunoassay are expected to be attained.