Rational Self-Assembly of Ordered Nanoparticle Composites using DNA Interactions

sinnointellectual Merit：这个结合计算和实验的项目专注于有序纳米粒子复合材料的工程，其自组装是由粒子之间的可逆DNA桥驱动的。金属或半导体纳米颗粒有序排列的创造有望使新材料（称为超材料）具有真正独特而有用的光学和电子特性。目前使用筛选库仑和空间相互作用来组装纳米粒子的方法非常依赖于粒子的细节。化学和大小。相比之下，DNA定向组装允许在多个纳米粒子物种之间进行特定吸引相互作用的矩阵工程，相互作用的强度和范围仅由DNA序列控制。该项目将具体解决以下两个主要研究目标。第一个目标是绘制出两组分纳米颗粒悬浮液的预期平衡相行为，作为两组分的相对结合强度和半径的函数。第二个目的是阐明成核和生长动力学在限制可获得的纳米复合材料结构和可实现的缺陷密度方面的作用。在这两个目标中，详细的模拟将提供对可达阶段的广泛调查；选定的结构随后将通过实验实现。在这些活动的同时，新的工具将被开发出来，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）。利用这些成分，这项工作将导致一种基于DNA的自组装方案，使有序纳米颗粒复合材料的烹饪书制造成为可能，其中形成的晶体结构是由DNA序列和几何形状决定的，而不是粒子化学。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电路以及超分辨率显微镜中找到应用。这个项目的目的是为合理设计这些材料奠定基本原则。作为这个项目的一部分开发的新工具应该具有广泛的适用性，远远超出这里概述的具体调查的直接范围。这个跨学科的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，鉴于克罗克和辛诺研究小组之间的合作历史，我们认为这相对容易实现。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模拟技术。此外，模拟和实验数据的丰富，视觉性质及其在非凡技术（例如隐形）中的潜在应用将促进费城公立学校高中生的推广工作，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.