Zero-Mode Waveguides for Single-Molecule Detection

描述（由申请人提供）：零模波导（ZMG）是一种新的和强大的技术，用于减少荧光光学检测系统中照射流体的体积。该方法已被证明允许前所未有的小观察体积，从而在检测和表征单分子的新能力。照明体积的减小提供了信噪比、信号背景比和时间分辨率的显著增益。Nanofluidics公司打算将这些结构商业化提供给工业和学术用户，以使单分子检测的研究和应用成为可能。已经确定了一个具有重大商业潜力的应用-单分子DNA测序策略，该策略需要信噪比，目前只能通过ZMG技术实现。当研究社区被提供访问ZMG时，预计会出现其他应用程序。ZMG的性能已得到证实，因此商业化的剩余技术风险参数是工艺一致性和生产成本。第一阶段计划的目标是解决与ZMG生产一致性相关的问题。首先，必须开发一种工具来测量ZMG的内部尺寸，这是传统检测技术无法实现的。我们建议推断的ZMG的光学特性的结构的尺寸通过比较光学测量与模拟。我们将使用有限元方法来模拟ZMG内部和周围的电磁场，以列表显示各种几何形状的荧光激发分布和偶极辐射逃逸效率。然后，将使用一维解析扩散模型来预测每个的预期荧光相关光谱。接下来，将使用相同的几何形状制造和测试ZMG，以验证模型并测量制造可变性。成功将定义为证明一致可达到低于1阿升的有效观察体积，直径变异性小于25%。完成第一阶段目标后，Nanofluidics，Inc.将提交SBIR第二阶段提案，根据该提案，我们将使用目前的方法制造设备，并将其置于beta测试场所，同时探索降低制造成本的方法。这种探索的范围将从第一阶段证明的工艺的渐进式改进到不需要昂贵的直写电子束光刻的新制造技术。

DESCRIPTION (provided by applicant): Zero-mode waveguides (ZMGs) are a new and powerful technique for reducing the volume of illuminated fluid in a fluorescence optical detection system. The method has been shown to allow unprecedented small observation volumes, resulting in new abilities in detecting and characterizing single molecules. Reduction of illuminated volume provides significant gains in signal-to-noise, signal-to-background and temporal resolution. Nanofluidics, Inc. intends to make these structures commercially available to industrial and academic users to enable research in and applications of single-molecule detection. One application with significant commercial potential has already been identified-- a single-molecule DNA sequencing strategy that requires a signal-to-noise that right now can only be attained with the ZMG technology. Other applications are expected to emerge when the research community is provided access the ZMGs. The performance of the ZMG has been proven, so the remaining technical risk parameters to commercialization are process consistency and production cost. The goals of this phase I program are to address the issues related to consistency in the production of ZMGs. First, it is essential to develop a tool to measure the interior dimensions of the ZMG, which is not possible with conventional inspection techniques. We propose to infer the dimensions of the structure from optical characteristics of the ZMG by comparison of optical measurements with simulation. We will use finite-element methods to simulate the electromagnetic fields in and around the ZMGs to tabulate both the fluorescence excitation profile and the efficiency of dipole radiation escape for a variety of geometries. Then a one-dimensional analytic diffusion model will be used to predict the fluorescence correlation spectra expected for each. Next, ZMGs will be fabricated and tested with the same geometries allowing validation of the models and measurement of fabrication variability. Success will be defined as demonstration of consistent attainability of sub 1-attoliter effective observation volumes, with variability in diameters of less than 25%. Upon completion of the phase I goals, Nanofluidics, Inc. will submit an SBIR phase II proposal under which we will make devices using the present methods and place them in beta test sites, while concurrently exploring methods of reducing the cost of manufacture. This exploration will range from incremental improvements of the process proven in Phase I to novel fabrication techniques that don't require expensive direct-write electron-beam lithography.