Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, United States.
Anal Chem. 2011 Nov 15;83(22):8636-41. doi: 10.1021/ac202095k. Epub 2011 Oct 21.
Despite multiple orbiter and landed missions to extraterrestrial bodies in the solar system, including Mars and Titan, we still know relatively little about the detailed chemical composition and quantity of organics and biomolecules in those bodies. For chemical analysis on astrobiologically relevant targets such as Mars, Europa, Titan, and Enceladus, instrumentation should be extremely sensitive and capable of analyzing a broad range of organic molecules. Microchip capillary electrophoresis (μCE) with laser-induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant markers but, to date, has lacked the necessary degree of automation for spaceflight applications. Here we describe a fully integrated microfluidic device capable of performing automated end-to-end analyses of amino acids by μCE with LIF detection. The device integrates an array of pneumatically actuated valves and pumps for autonomous fluidic routing with an electrophoretic channel. Operation of the device, including manipulation of liquids for sample pretreatment and electrophoretic analysis, was performed exclusively via computer control. The device was validated by mixing of laboratory standards and labeling of amino acids with Pacific Blue succinimidyl ester followed by electrophoretic analysis. To our knowledge, this is the first demonstration of completely automated end-to-end μCE analyses on a single, fully integrated microfluidic device.
尽管太阳系中有多个轨道飞行器和着陆任务对地球以外的天体进行了探索，包括火星和泰坦，但我们对这些天体中有机物和生物分子的详细化学成分和数量仍然知之甚少。对于火星、木卫二、土卫六和土卫二等天体生物学相关目标的化学分析，仪器应该具有极高的灵敏度，并能够分析广泛的有机分子。带有激光诱导荧光（LIF）检测的微芯片毛细管电泳（μCE）提供了这种必需的灵敏度，并针对广泛的相关标记物，但迄今为止，它缺乏用于太空飞行应用的必要自动化程度。在这里，我们描述了一种完全集成的微流控装置，能够通过带有 LIF 检测的 μCE 对氨基酸进行自动端到端分析。该设备集成了一系列气动驱动的阀和泵，用于与电泳通道的自主流体路由。该设备的操作，包括用于样品预处理和电泳分析的液体操作，完全通过计算机控制进行。该设备通过混合实验室标准品和用太平洋蓝琥珀酰亚胺酯标记氨基酸进行了验证，然后进行电泳分析。据我们所知，这是首次在单个完全集成的微流控设备上演示完全自动化的端到端 μCE 分析。
