Highly structured optical materials based on protein containers and plasmonic nanoparticles for the manipulation of light at the nanoscale

在这个项目中，将利用蛋白质容器和纳米颗粒建立一种合成光学材料的策略。人工组装的材料将能够在纳米尺度上操纵光，这在超材料和传感、等离子体光学或光收集等应用中非常重要。为此，等离子体金纳米粒子和量子点将被安排成高度结构化的等离子体和能量转移材料。目前，纳米颗粒材料制造面临的主要挑战是低阶组装、小畴尺寸和粒子间距离长。这些限制将通过使用蛋白质容器作为原子精确的配体外壳来克服。以蛋白质容器为构建块，纳米颗粒将以高精度组装成具有光学特性的中尺度材料，这些材料是由组件之间的相互作用产生的。随着蛋白质容器计算重新设计的最新进展，现在有可能以高度跨学科的方式将这些结果与纳米粒子合成和蛋白质晶体学结合起来。一种新型的蛋白质基材料将通过使用一种创新的设计方法实现，该方法将两个相反带电的蛋白质容器作为构建块。将生成两种不同类型的纳米粒子组成的二元纳米粒子超晶格。对于能量转移材料，荧光量子点将与等离子体纳米粒子共同组装，以实现粒子之间的能量转移。混合蛋白-纳米颗粒材料具有高的纳米颗粒含量和较短的颗粒间距（<10 nm，小于颗粒直径）。这对于基于强近场相互作用（如粒子之间的等离子体耦合）的涌现特性至关重要，但由于宽敞的连接材料，目前的方法难以实现。由于蛋白质支架是独立于纳米颗粒货物的，这种模块化的方法，加上材料的二元性质，将能够通过选择纳米颗粒含量、组装类型和蛋白质容器类型来调整光学特性。该项目将对基于等离子体纳米粒子和量子点的光学材料的合成和表征做出重大贡献，并将在纳米尺度上对此类系统的光-物质相互作用提供更好的理解。此外，具有等离子体或能量转移特性的材料具有潜在的应用，如等离子体波导或纳米激光器（spasers），用于在纳米尺度上操纵光信号。

In this project, a synthetic strategy towards optical materials will be established using protein containers and nanoparticles. The artificially assembled materials will be able to manipulate light at the nanoscale, which is important in metamaterials and for applications such as sensing, plasmon optics or light harvesting. To this end, plasmonic gold nanoparticles and quantum dots will be arranged into highly structured plasmonic and energy-transfer materials. Currently, major challenges in nanoparticle material fabrication are low-order assembly, small domain sizes and long interparticle distances. These limitations will be overcome by using protein containers as an atomically precise ligand shell. With protein containers as building blocks, nanoparticles will be assembled with high precision into mesoscale materials with optical properties that emerge from interactions between the components. With the recent advances in computational redesign of protein containers, it is now possible to combine these results with nanoparticle synthesis and protein crystallography in a highly interdisciplinary fashion. A new type of protein-based material will be realized by using an innovative design approach with two oppositely charged protein containers as building blocks. Binary nanoparticle superlattices with two different types of nanoparticles will be generated. For energy-transfer materials, fluorescent quantum dots will be co-assembled with plasmonic nanoparticles to enable energy transfer between the particles. The hybrid protein-nanoparticle materials will have a high nanoparticle content and display short interparticle distances (<10 nm, below the particle diameter). This is essential for emergent properties based on strong near-field interactions such as plasmonic coupling between the particles, but difficult to achieve with current approaches due to spacious linker materials. Because the protein scaffold is independent of the nanoparticle cargo, this modular approach, together with the binary nature of the materials, will enable tuning of the optical properties by choice of nanoparticle content, assembly type and protein container type. The proposed project will make a significant contribution to the synthesis and characterization of optical materials based on plasmonic nanoparticles and quantum dots and will provide improved understanding of light-matter interactions at the nanoscale for such systems. Furthermore, materials with plasmonic or energy-transfer properties have potential application as plasmonic waveguides or nanoscopic lasers (spasers) for manipulation of light signals at the nanoscale.