SBIR Phase I: Improved Substrates for Single Molecule Detection

这个小型企业创新研究第一阶段项目将开发用于增强附近分析物荧光信号的底物。这将通过利用规则间隔的金属纳米颗粒的二维阵列来实现，从而产生表面等离子体的传播模式。这些表面等离子体共振将通过改变纳米颗粒阵列的尺寸、组成和间距来调节，以匹配荧光团的荧光发射。或者，高介电纳米材料阵列将用于产生光子晶体，用于聚焦和增强允许的频率，其中缺陷用作局部捕获光的位点。这些纳米颗粒阵列将组装使用二维蛋白质晶体作为模板，如前所述。将荧光团定位到阵列表面将有利于单分子检测，这将在许多类型的基于荧光的生物传感器中具有广泛的应用，例如，将核酸或抗体探针附着到表面。将这些探针连接到荧光增强底物上将提高这些测定的灵敏度。此外，这些基板将允许更强大的单分子检测应用，减少与荧光漂白和通过集中的探针区域到更小的体积相关的问题。这将有利于蛋白质折叠、酶动力学和反应机理等领域的基础研究，并促进生物传感器的发展，以检测低水平的病毒或微量的生物战剂。

This Small Business Innovation Research Phase I project will develop substrates for enhancing the fluorescence signal from nearby analytes. This will be achieved by utilizing two-dimensional arrays of regularly spaced metallic nanoparticles thereby generating propagating modes of surface plasmons. These surface plasmon resonances will be tuned by varying the size, composition, and spacing of the nanoparticle array to match the fluorescence emission of the fluorophore. Alternatively, arrays of high dielectric nanomaterials will be used to generate photonic crystals serving to focus and enhance the allowed frequencies with defects serving as sites for the local trapping of light. These nanoparticle arrays will be assembled using two-dimensional protein crystals as templates as previously reported. Localization of the fluorophore to the surface of the arrays will be beneficial for single molecule detection.This will have broad application in many types of fluorescence-based biosensors where, for example, nucleic acid or antibody probes are attached to a surface. Attaching these probes to a fluorescence-enhancing substrate will improve the sensitivity of these assays. Furthermore, these substrates will allow more robust single molecule detection applications by reducing problems associated with fluorophore bleaching and byconcentrating the probe region to smaller volumes. This will benefit basic research in areas such as protein folding, enzyme kinetics, and reaction mechanisms as well as promote the development of biosensors to detect low levels of virus or trace amounts of biological warfare agents.