Rational Self-Assembly of Ordered Nanoparticle Composites using DNA Interactions

CBET-0829045 SinnoIntellectual Merit：这个计算和实验相结合的项目专注于有序纳米颗粒复合材料的工程，其自组装是由颗粒之间的可逆DNA桥驱动的。 金属或半导体纳米粒子有序阵列的创建有望使新材料（称为超材料）具有真正独特和有用的光学和电子特性。 目前的方法，这样的纳米粒子组装使用屏蔽库仑和空间相互作用敏感地依赖于粒子的细节？化学和大小。 相比之下，DNA定向组装允许在多个纳米颗粒物质之间设计特定吸引相互作用的矩阵，相互作用强度和范围仅由DNA序列控制。 本项目将具体解决以下两个主要研究目标。 第一个目的是绘制出预期的平衡相行为的两个组件的纳米颗粒悬浮液作为相对结合强度和半径的两个组件的函数。 第二个目的是阐明成核和生长动力学在限制可访问的纳米复合结构和可实现的缺陷密度中发挥的作用。 在这两个目标，详细的模拟将提供一个广泛的调查可访问的阶段，选定的结构随后将实现实验。 在开展这些活动的同时，还将开发新的工具，用于更精确的模拟（具有相关移动的蒙特卡罗）和实验（用于纳米结构表征的超分辨率显微镜）。 使用这些组件，这项工作将导致基于DNA的自组装方案，使有序纳米颗粒复合材料的食谱制造，其中形成的晶体结构是由DNA序列和几何形状，而不是颗粒化学决定的。 更广泛的影响：超材料，特别是那些具有负折射率等特性的材料，有望在未来的光子和等离子体电路以及超分辨率显微镜中找到应用。 该项目的目的是制定合理设计此类材料的基本原则。 作为该项目的一部分开发的新工具应具有广泛的适用性，远远超出了这里概述的具体调查的直接范围。这个跨学科项目将为研究生和本科生提供充足的培训机会。 参与该项目的两名研究生都将积极参与计算和实验方面的工作，我们相信，鉴于克罗克和辛诺研究小组之间的合作历史，这一点相对容易实现。 学生将接触到最先进的工具包，其中包括纳米粒子功能化，先进的显微镜和数值建模技术。 此外，模拟和实验数据的丰富、可视化性质及其在显着技术（如隐形）中的潜在应用将促进费城公立学校高中生的外联工作，并传达科学研究的兴奋。

CBET-0829045SinnoIntellectual Merit: This combined computational and experimental project is focused on the engineering of ordered nano-particle composites whose self-assembly is driven by reversible DNA bridges between particles. The creation of ordered arrays of metallic or semiconductor nanoparticles promises to enable new materials, called metamaterials, having truly unique and useful optical and electronic properties. Current approaches to such nano-particle assembly using screened coulomb and steric interactions depend sensitively on details of the particles? chemistry and size. In contrast, DNA-directed assembly allows the engineering of a matrix of specific attractive interactions among multiple nano-particle species, with the interaction strength and range controlled by DNA sequence alone. This project will specifically address the following two principal research aims. The first aim is to map out the expected equilibrium phase behavior of two component nano-particle suspensions as a function of the relative binding strengths and radii of the two components. The second aim is to elucidate the role that nucleation and growth kinetics play in limiting the accessible nano-composite structures and achievable defect densities. In both aims, detailed simulations will provide a broad survey of accessible phases; selected structures subsequently will be realized experimentally. Concurrent with these activities, new tools will be developed both for more accurate simulation (Monte Carlo with correlated moves) and experiment (super-resolution microscopy for nanostructural characterization). Using these components, this effort will lead to a DNA-based self-assembly scheme to enable the cook-book fabrication of ordered nanoparticle composites, where the crystal structures formed are determined by DNA sequence and geometry rather than particle chemistry. Broader Impacts: Metamaterials, especially those with properties such as a negative index of refraction are expected to find applications in future photonic and plasmonic circuitry, as well as super resolution microscopy. The aim of this project is to lay down fundamental principles for rationally designing such materials. The new tools developed as part of this project should have broad applicability well beyond the immediate scope of the specific investigations outlined here.This interdisciplinary project will provide ample opportunities for student training at both the graduate and undergraduate levels. Both of the graduate students involved in this project will expected to be actively involved in both the computational and experimental facets, which we believe is relatively easy to realize given the history of collaboration between the Crocker and Sinno research groups. Students will be exposed to a state-of-the-art toolkit which includes nano particle functionalization, advanced microscopy and numerical modeling techniques. Moreover, the rich, visual nature of the simulation and experimental data and their potential application in remarkable technology e.g. invisibility will facilitate outreach efforts to high-school students in the Philadelphia public schools and convey the excitement of scientific research.