Biochemical Sensors Utilizing Cavity Ring-Down Spectroscopy

ZareMPS-0313996这一小额探索性研究(SGER)奖支持对新出现的基于腔环形光谱技术的传感器作为凝聚相生物分子探测器的适用性的研究，特别是对潜在的生物恐怖主义制剂的研究。为了使腔衰荡光谱(CRDS)对生物传感器技术具有非凡的敏感性，将采取四种发展战略。每种方法在实现、选择性和敏感性方面都有自己的潜在优势。第一种方法是使用入射窗口与出射窗口成布鲁斯特角的单元，以使插入光学腔内时的吸收损失降至最低。该装置的目的是使检测器小型化，以便能够分析非常少量的液体。这种设备在与毛细管电泳或芯片实验室等微分离相结合时具有特别的前景。第二种方法是使用光学腔，其中的光通过消逝波与周围环境进行光学接触。这种装置对光学接触表面的吸收变化很敏感。它的优点是将光线保持在内部，这样它就不会受到与表面接触的介质中的浑浊问题的影响。第三种方法是使用与CRDS耦合的表面等离子体共振(SPR)。它对液-表面界面也很敏感，其价值将取决于分析物敏感的探针分子连接到SPR中使用的金属(金或银)表面的容易程度。第四种方法是液体与构成光学腔的两面镜子直接接触。到目前为止，这种方法是最容易实施的，将对限制其操作的因素进行评估，特别是在分析物选择性方面。本研究为生物大分子的检测和定量提供了重要的应用基础。这项活动由数学和物理科学局的多学科活动办公室和生物科学局生物基础设施司的仪器和仪器开发方案共同支助。

AbstractZareMPS-0313996This Small Grants for Exploratory Research (SGER) award supports research into the applicability of the newly emerging technique of Cavity Ring-Down Spectroscopy - based sensors as probes for biomolecules in the condensed phase, with particular emphasis on potential bioterrorism agents. Four developmental strategies will be pursued to bring the extraordinary sensitivity of Cavity Ring-Down Spectroscopy (CRDS) to biosensor technology. Each has its own potential advantages for implementation, selectivity, and sensitivity. The first approach is the use of a cell whose entrance and exit windows are at Brewster's angle to minimize absorption losses when inserted inside an optical cavity. The purpose of this device is to miniaturize the detector so that very small volumes of liquid can be analyzed. Such a device has particular promise when coupled to microseparations, such as capillary electrophoresis or lab on a chip. The second approach is the use of an optical cavity in which the light makes optical contact with the surroundings by means of an evanescent wave. This device is sensitive to absorption changes at the surface where the optical contact is made. It has the advantage of keeping the light on the inside so that it is immune to questions of turbidity in the medium in contact with the surface. The third approach is the use of surface plasmon resonance (SPR) coupled to CRDS. It is also sensitive to the liquid-surface interface and its value will depend on the ease with which analyte-sensitive probe molecules can be coupled to the metal (gold or silver) surface used in SPR. The fourth approach is the direct contact of the liquid with the two mirrors that constitute the optical cavity. This approach is by far the simplest to implement, and an assessment will be made of what limits its operations, particularly in regard to analyte selectivity. This research could well provide the basis for broad and important applications in the detection and quantification of biomolecules. This activity is jointly supported by the Office of Multidisciplinary Activities in the Directorate for Mathematical and Physical Sciences and by the Instrumentation and Instrument Development Program in the Division of Biological Infrastructure in the Directorate for Biological Sciences.