Nanoscale Curvature Effects on the Properties of Anisotropic Nanomaterials

化学系的大分子、超分子和纳米化学(MSN)项目获得这一奖项，资助西北大学的Teri Odon教授研究一种特定类型的纳米颗粒--金纳米星--可以有效地合成。由金和银等贵金属制成的纳米粒子在从化学传感器到光学成像探测器再到抗菌剂的一系列应用中都很有前景。然而，制备和控制非球形金属纳米颗粒的特定特征(尖端、边缘、曲线)仍然是具有挑战性的。这些纳米特征预计将非常重要，因为它们的尺寸接近分子的大小。该项目旨在通过调整纳米颗粒表面的化学成分来获得具有所需特征的纳米恒星。这些独特的纳米材料的更广泛的影响包括将一锅金纳米STAR合成与一年级普通化学中关于胶体金纳米颗粒的现有实验室相结合。此外，专注于纳米科学的大一新生研讨会正在开发类似于解释纳米概念的“Ted Ed”类视频的项目。这项建议旨在确定支持正曲率、负曲率和中性曲率的独特曲率区域的各向异性纳米材料如何同时显示出不同于对称(球形)或细长(棒状)纳米颗粒的特性。金纳米星可以作为一种独特的模型系统，因为它们可以通过无籽方法合成，从而产生不同数量的树枝，其厚度和长度可调。这项工作旨在解决单粒子水平上的无籽生长机制，并确定如何通过物理后处理来优化金纳米星形样品的纯度。其他目标包括确定与配体连接相关的金纳米星的结构-活性关系。这项关于纳米曲率的工作的主要成果包括：(1)确定Good‘s缓冲液中负责形成不同分支数、分支长度和负曲率的金纳米星的官能团；(2)利用原位透射电子显微镜在单粒子水平上解析金纳米星的生长机制；(3)确定具有二级结构(双链、环状、四链)的生物配体优先吸附在金纳米星上的位置。

With this award the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Chemistry Division is funding Professor Teri Odom at Northwestern University to study a specific type of nanoparticle -gold nanostars-that can be efficiently synthesized. Nanoparticles made from noble metals such as gold and silver are promising in a range of applications, from chemical sensors to optical imaging probes to anti-bacterial agents. However, preparing and controlling specific features (tips, edges, curves) on metal nanoparticles with non-spherical shapes are still challenging. These nanoscopic features are expected to be important as their sizes approach that of molecules. The project aims to obtain nanostars with desired features by tuning the chemistry at the nanoparticle surface. Broader impacts of these unique nanomaterials include integrating the one-pot gold nanostar synthesis with an existing lab on colloidal gold nanoparticles in freshmen general chemistry. In addition, freshman seminars focusing on nanoscience are developing projects similar to 'Ted Ed'-like videos explaining nano-concepts.This proposal seeks to determine how anisotropic nanomaterials that support unique curvature regions of positive, negative, and neutral curvature simultaneously exhibit properties distinct from symmetric (spherical) or elongated (rod-like) nanoparticles. Gold nanostars can serve as a unique model system since they can be synthesized through a seedless method resulting in distinct numbers of branches with tunable thicknesses and lengths. This work aims to resolve the mechanism of seedless growth at the single-particle level as well as determine how gold nanostar sample purity can be optimized by physical post-processing. Other goals include determining the structure-activity relationships of gold nanostars related to ligand attachment. Major outcomes of this work on nanoscale curvature include: (1) identifying functional groups in Good's buffers responsible for the formation gold nanostars with different branch numbers, branch lengths, and negative curvature degrees; (2) resolving the growth mechanism of gold nanostars at the single-particle level using in situ transmission electron microscopy; and (3) determining where biological ligands having secondary structure (double-stranded, looped, quadruplex) preferentially adsorb on the gold nanostars.