Johnson Mitchell E, Landers James P
Duquesne University, Department of Chemistry and Biochemistry, Pittsburgh, PA 15282, USA.
Electrophoresis. 2004 Nov;25(21-22):3513-27. doi: 10.1002/elps.200406086.
Laser-induced fluorescence is an extremely sensitive method for detection in chemical separations. In addition, it is well-suited to detection in small volumes, and as such is widely used for capillary electrophoresis and microchip-based separations. This review explores the detailed instrumental conditions required for sub-zeptomole, sub-picomolar detection limits. The key to achieving the best sensitivity is to use an excitation and emission volume that is matched to the separation system and that, simultaneously, will keep scattering and luminescence background to a minimum. We discuss how this is accomplished with confocal detection, 90 degrees on-capillary detection, and sheath-flow detection. It is shown that each of these methods have their advantages and disadvantages, but that all can be used to produce extremely sensitive detectors for capillary- or microchip-based separations. Analysis of these capabilities allows prediction of the optimal means of achieving ultrasensitive detection on microchips.
激光诱导荧光是化学分离检测中一种极其灵敏的方法。此外，它非常适合小体积检测，因此广泛应用于毛细管电泳和基于微芯片的分离。本综述探讨了实现亚zeptomole、亚皮摩尔检测限所需的详细仪器条件。实现最佳灵敏度的关键是使用与分离系统相匹配的激发和发射体积，同时将散射和发光背景降至最低。我们讨论了如何通过共聚焦检测、90度毛细管上检测和鞘流检测来实现这一点。结果表明，这些方法各有优缺点，但都可用于制造基于毛细管或微芯片分离的极其灵敏的检测器。对这些能力的分析有助于预测在微芯片上实现超灵敏检测的最佳方法。
