Shape-Controlled Nanostructures of Metals

该项目将为大规模合成具有良好控制形状和性能的金属纳米结构奠定科学基础。合成方法将基于多元醇工艺，其中多元醇（如乙二醇）作为溶剂和还原剂，有机聚合物（如聚乙烯基吡咯烷酮）（PVP）作为封盖剂。将设计和实施一系列新的实验，专门解决各种基本问题，例如，更深入地了解和更好地控制溶液阶段的成核和生长；快速筛选和选择适合形成特定形状的旋盖剂，并阐明旋盖剂所起的作用。本研究还将充分考察一些阴离子（如氯化物和溴化物）在控制成核步骤中形成的种子的形状和结晶度方面的功能。此外，该项目将研究与这些金属纳米结构相关的一些有趣的应用，例如，表面等离子体，光学传感，对比度增强光学成像和多相催化。该计划将透过多学科研究及合作，加强对研究生及本科生的教育。它还将为PI提供一个平台，让本科生（特别是来自社区学院和少数民族院校的学生）和高中生在他的实验室进行研究。该项目将开发一种通用方法，用于大规模合成具有广泛可控形状（例如立方体、棒状、线状、准球体和薄板）的金属纳米结构。这种控制将使我们能够定制纳米结构的电子、光学和催化特性。该研究还将更好地理解纳米结构材料固相合成的成核和生长机制，以及快速筛选特定形状演变所需的实验条件的新工具。更重要的是，这项研究将提供一种纳米结构材料，它可以作为一个新的平台，从根本上改变癌症的诊断、成像和治疗方式。例如，银和金纳米结构可以以多种不同的配置用于检测具有极高灵敏度的癌症相关分子。由于它们在近红外区域（软组织的透明窗口）具有可调谐和极高的消光系数，因此它们在生物医学应用中也具有巨大的潜力，例如癌症的光热治疗和肿瘤细胞的对比度增强光学成像。研究生和本科生的教育将通过多学科研究和合作得到加强。它还将为PI提供一个自然的工具，让本科生（特别是来自社区学院和少数民族机构的学生）和高中生在他的实验室进行研究。

This project will develop a scientific base for the large-scale synthesis of metallic nanostructures with well-controlled shapes and properties. The synthetic approach will be based on the polyol process, where a polyol such as ethylene glycol serves as both solvent and reducing agent and an organic polymer such as poly(vinyl pyrrolidone) (PVP) acts as the capping agent. A series of new experiments will be designed and performed to specifically address various fundamental issues that include, for example, a deeper understanding and better control of nucleation and growth in the solution phase; rapid screening and selection of a suitable capping agent for the formation of a specific shape, and elucidation of the role(s) played by the capping agents. This research will also fully examine the functions of some anions (e.g., chloride and bromide) in controlling the shape and crystallinity of seeds formed in the nucleation step. In addition, this project will investigate some intriguing applications associated with these metallic nanostructures including, for example, surface plasmonics, optical sensing, contrast-enhanced optical imaging, and heterogeneous catalysis. The project will enhance the education of both graduate and undergraduate students through multidisciplinary research and collaboration. It will also provide a platform for the PI to engage undergraduate students (in particular, those from community colleges and minority institutions) and high school students to conduct research in his laboratory.%%%This project will develop a generic approach to the large-scale synthesis of metallic nanostructures with a broad range of controllable shapes (e.g., cubes, rods, wires, quasi-spheres, and thin plates). Such control will enable us to tailor the electronic, optical, and catalytic properties of nanostructures. The research will also provide a better understanding of the nucleation and growth mechanisms associated with solution-phase synthesis of nanostructured materials, as well as new tools for the rapid screening of experimental conditions required for the evolution of a specific shape. More importantly, the research will provide a class of nanostructured materials that can serve as a new platform to radically change the way cancer is diagnosed, imaged, and treated. For example, the silver and gold nanostructures can be used in a number of different configurations for the detection of cancer-related molecules with extremely high sensitivities. Due to their tunable and extremely high extinction coefficients in the near-IR region (the transparent window of soft tissues), they also have great potential in biomedical applications such as photothermal therapy of cancer and contrast-enhanced optical imaging of tumor cells. The education of both graduate and undergraduate students will be enhanced through multidisciplinary research and collaborations. It will also provide a natural vehicle for the PI to engage undergraduate students (in particular, those from community colleges and minority institutions) and high school students to conduct research in his laboratory.