ADVANCED FABRICATION AND SENSOR DEVELOPMENT

DNA基因分型和测序的分析方法与从DNA源材料开始提取遗传信息的多步骤处理系统相关联。在传统的方法中，处理系统对微升体积的反应样品进行处理，并配备相应的液体处理装置和电泳分析设备。项目3将为DNA测序和基因分型提供改进的纳升体积处理组件的组件级设计和测试。为了实现高质量、连续的DNA测序目标，需要在荧光检测和凝胶电泳方面进行重大改进。新的或改进的制造技术也将检查生化相容性，易于制造，成本，或再现性。项目中开发的所有组件都保留了最终集成到项目1的复杂系统中的目标。项目3有三个具体目标：1)开发聚合物硅微加工元件。薄膜聚合物通道和聚合物基板上的成型/压花图案都将用于集成器件结构。薄膜法将扩展到更厚的通道壁，从而减少蒸发液体损失。热塑性塑料和硅表面的键合也将使用两种类型的聚合物处理方法来产生密封通道。2)研制高灵敏度荧光探测器。我们构建的初始二极管检测器将进行改进，以(a)最大化其对DNA荧光信号的响应，(b)最小化其暗电流噪声，以及(c)将检测器与电泳阶段电隔离。我们预计检测器的信噪比将提高10到100倍。3)非共线荧光激发的发展。在目前的装置布置中，激发照明与探测器共线。我们将开发非共线照明方案，依赖于聚合物波导上的微机械反射表面。

Analysis methods for DNA genotyping and sequencing are linked into multi-step processing systems that begin with DNA source material and extract genetic information. In conventional methods, the processing system operates on batches of microliter-volume reaction samples, together with matched liquid handling devices and electrophoretic analysis equipment. Project 3 will provide component-level design and testing of improved nanoliter-volume processing components for DNA sequencing and genotyping. To fulfill the goal of high-quality, continuous DNA sequencing significant improvements in fluorescence detection and gel electrophoresis will be required. New or improved fabrication technologies will also be examined for biochemical compatibility, ease of fabrication, cost, or reproducibility. All of the components developed in the Project retain the target of eventual integration into the complex system of Project 1. Project 3 has three Specific Aims: 1) Development of polymer-silicon micromachined components. Both thin film polymer channels and molding/embossing patterns on polymer substrates will be used for integrated device construction. Thin film methods will be extended to thicker channel walls, thereby reducing evaporative liquid loss. Bonding of thermoplastic and silicon surfaces to generate hermetic sealed channels will also be developed using two types of polymer handling methods. 2) Development of enhanced sensitivity fluorescence detectors. The initial diode detector we have constructed will be improved to (a) maximize its response to the DNA fluorescent signal, (b) minimize its dark current noise, and (c) electrically isolate the detector from the electrophoresis stage. We anticipate at 10- to 100-fold improved in the signal to noise ratio for the detector. 3) Development of non-collinear fluorescence excitation. In the current device arrangement, the excitation illumination is collinear with the detector. We will develop non-collinear illumination schemes relying on either micromachined reflecting surfaces on polymer wave-guides.