SELF BAR-CODED COLLOIDAL METAL NANOPARTICLES

当今生命科学研究的一个共同点是需要组织和访问复杂分子系统中固有的大量潜在信息。 在药物发现中，组合文库中的珠粒被标记有一系列有机分子以便于它们的鉴定。 基因组学项目依赖于空间限定的平面阵列来监测数百或数千种不同寡核苷酸的反应。在宏观世界中，复杂的系统通常被条形码简化，条形码是一种极大地简化数据收集和识别的技术。 该提案涉及纳米级金属条形码。 其基础在于最近开发的化学方法，以生产独立的、圆柱形的胶体金属纳米颗粒（宽度为30 - 200 nm，长度为0.4 - 4 μ m），其中金属组成可以沿长度沿着交替（例如Pt-Au-Pt-Au-Pt），并且其中金属片段可以是长度调谐的和选择性化学官能化的。 该提案进一步利用了这一发现，即反射率的内在差异允许通过常规光学显微镜观察单个棒中的金属段。 这些创新使条形码（和条形码阅读器）的概念与生物学相关的长度尺度有关。 如果开发得当，这些新材料可能在生命科学领域产生巨大影响，这些领域包括组合有机合成、基因表达分析、单核苷酸多态性检测和基因分型、高通量筛选、同步荧光检测、荧光标记、荧光标记和荧光标记。（多像素）生物测定，甚至流式细胞术：简而言之，在任何需要或期望识别和追踪大量分子或分子组装体的活动中。 因此，该提议旨在开发和/或改进条形码合成、条形码读出、生物测定读出和条形码表面化学，以便最大化它们的潜在效用。为此，拟议工作的具体研究里程碑包括：（一）使用多达六种不同的金属制作多达十二个可区分段的金属条形码;（二）演示可编程的纳米级条形码自动合成;（三）使高分辨率条形码识别适应于窄的、时变的和宽的、静态的视场;（四）使高分辨率条形码识别适应于窄的、时变的和宽的、静态的视场;（五）使高分辨率条形码识别适应于窄的、时变的和宽的、静态的视场;（六）使高分辨率条形码识别适应于窄的、时变的和宽的、静态的视场;（七）使高分辨率条形码识别适应于窄的、时变的和宽的、静态的视场。（iv）开发能够同时进行条形码ID和荧光生物测定读出的仪器;（v）演示一种新颖且高度通用的检测机制，该机制允许在许多不同条形码的混合物中，每种条形码具有不同的化学性质，仅那些经历化学反应的条形码被可视化;以及（vi）在单个条形码上同时定量三种不同的分析物。

A common thread in life science research today is the need to organize and access the vast array of potential information inherent in complex molecular systems. In drug discovery, the beads in combinatorial libraries are tagged with series of organic molecules to facilitate their identification. Genomics projects rely on spatially-defined planar arrays to monitor reactions of hundreds or thousands of different oligonucleotides. In the macroscopic world, complex systems are often simplified by bar coding, a technology that tremendously streamlines data collection and identification. This proposal relates to nanometer-scale metallic bar codes. Its foundation rests on very recently-developed chemistry to produce free-standing, cylindrically-shaped colloidal metal nanoparticles (30 - 200 nm in width, 0.4 - 4 mum length) in which the metal composition can be alternated (e.g. Pt-Au-Pt-Au-Pt) along the length, and in which the metal segments can be both length-tuned and selectively chemically functionalized. The proposal further exploits the finding that intrinsic differences in reflectivity, permit metal segments in individual rods to be visualized by conventional optical microscopy. These innovations have brought the notion of the bar code (and the bar code reader) to biologically-relevant length scales. If properly developed, these novel materials could have an enormous impact in life science, in areas as diverse as combinatorial organic synthesis, analysis of gene expression, detection of single nucleotide polymorphisms and genotyping, high throughput screening, simultaneous (multipexed) bioassays, and even flow cytometry: in short, in any activity in which identifying and tracking a large number of molecules or molecular assemblies is necessary or desirable. Accordingly, this proposal aims to develop and/or improve bar code synthesis, bar code readout, bioassay readout, and bar code surface chemistry, so as to maximize their potential utility. To that end, specific research milestones for the proposed work include the following: (i) fabrication of metallic bar codes with up to twelve distinguishable segments, using up to six different metals; (ii) demonstration of programmable, automated synthesis of nanoscale bar codes; (iii) adaptation of high-resolution bar code identification (ID) to both narrow, time-varying and wide, static fields of view; (iv) development of instrumentation capable of simultaneous bar code ID and fluorescence bioassay readout; (v) demonstration of a novel and highly general detection mechanism that allows in a mixture of many different barcodes, each with different chemistry, only those undergoing a chemical reaction to be visualized; and (vi) simultaneous quantitation of three different analytes on a single bar code.