CAREER: Hierarchical self-assembly of photonic devices from patchy colloids: deciphering the reflectin-photonic alphabet

摘要：该奖项由宾夕法尼亚大学材料研究部生物材料项目和化学、生物工程、环境和运输系统部纳米生物传感器项目（ENG/CBET）共同资助，旨在研究软体动物中一类蛋白质的自组装。软体动物是指乌贼、章鱼、蛞蝓、蛤蜊和牡蛎等动物。这些动物中有很多都是惊人的彩虹色，这种彩虹色被用来伪装，用来发信号，在巨型蛤的例子中，用于优化与共生藻类的光合作用。该项目旨在了解这些彩虹结构的演变，并了解它们的结构是如何从制造它们的蛋白质中产生的。为此，PI将利用海洋动物收集、材料表征技术和分子动力学建模的独特见解。这些结构的层次有序复杂性通常远远超过了目前的合成制造能力，因此了解动物如何制造这些光学材料将为制造小于一微米的层次长度尺度的材料提供洞察力。该项目的教育和研究活动与PI在开发生命科学入门物理课程（IPLS）中发挥主导作用相结合，这是宾夕法尼亚大学物理系的核心需求。研究生将接受尖端材料表征技术以及生物化学和生物领域工作的高度跨学科培训。该奖项还将资助费城公立学校的高中生暑期实习，这些学生通过参加宾夕法尼亚大学的暑期物理夏令营而被确定为具有科学天赋。这些实习的目标是提供研究经验和实践知识的机会，帮助这些学生在进入名牌大学时具有竞争力。最终目标是能够增加对STEM职业感兴趣的学生人数。技术摘要：软体动物，如鱿鱼、章鱼和蛤蜊，构建了一系列具有惊人光学/光子复杂性和复杂性的活体光学装置，如结构伪装涂层、渐变折射率透镜、太阳辐射分布器和波长特定光导。与鱼类、蝴蝶和鸟类的虹彩结构不同，软体动物的“虹彩细胞”是由仍然活着的细胞形成的，高指数部分是由活跃细胞质中密集的蛋白质组合产生的。这些光学共振细胞似乎比其他类群的系统具有更多的结构多样性，并且已经进化到能够解决比任何其他动物群体更广泛的进化光学问题，例如水下视觉，发射伪装，反射伪装以及有效光合作用的光分布。关于鱿鱼反射蛋白和s -结晶蛋白的一些新观察表明，“斑块胶体”是理解这些活光子系统组装的最翔实的理论范式。该项目将使用分子动力学建模、结构表征和海洋学收集来描述组成这些活光子系统的反射蛋白是否以及如何自组装成观察到的生物光子结构。

Non-Technical Abstract:This CAREER Award by the Biomaterials program in the Division of Materials Research, and co-funded by the Nano-Biosensors Program in the Division of Chemical, Bioengineering, Environmental and Transport Systems (ENG/CBET) to the University of Pennsylvania, is to study the self-assembly of a class of proteins found in molluscan animals. Mollusks are animals such as squids, octopuses, slugs, clams and oysters. Many of these animals are strikingly iridescent, and this iridescence is used for camouflage, for signaling, and in the case of giant clams, for optimization of photosynthesis with symbiotic algae. This project seeks to understand the evolution of these iridescent structures, and to understand how their structures emerge from the proteins that make them. To do this, the PI will use a unique combination of insights from oceanographic animal collections, materials characterization techniques, and molecular dynamics modeling. The hierarchically ordered complexity of these structures often far exceeds the current capabilities of synthetic fabrication, so understanding how animals make these optical materials will provide insight into fabrication of materials with hierarchical length scales smaller than a micron. The education and research activities of this project are well integrated with the PI playing a leading role in developing an introductory physics for life sciences curriculum (IPLS) which is a core need in the Department of Physics at UPenn. Graduate students will receive highly interdisciplinary training in cutting-edge materials characterization techniques as well as biochemistry and biological field work. This award will also fund summer internship for high school students in the Philadelphia public schools who have been identified as scientifically talented via their participation in the University of Pennsylvania's summer physics camp. The goal of these internships is to provide opportunities for research experiences and practical knowledge that help make these students competitive for admission to highly selective colleges and universities. The ultimate goal is to be able increase the number of students interested in STEM careers. Technical Abstract:Molluscan animals such as squids, octopuses and clams build an array of living optical devices of astounding optical/photonic sophistication and complexity, such as structural camouflaging coatings, graded index lenses, solar radiance distributors, and wavelength-specific light guides. Unlike the iridescent structures in fish, butterflies and birds, the "iridocytes" in molluscs are formed from still-living cells, with the high-index portions generated by dense assemblies of protein in the active cytoplasm. These optically resonant cells seem to be allowed more structural diversity than systems in other taxa, and have evolved to solve a wider array of evolutionary optical problems than in any other animal group, such as underwater vision, emissive camouflage, reflective camouflage, and distribution of light for efficient photosynthesis. Several new observations about reflectin proteins and S-crystallins from squids show that "patchy colloids" is the most informative theoretical paradigm for understanding assembly of these living photonic systems. This project will use molecular dynamics modeling, structural characterization, and oceanographic collection to describe whether and how the constituent reflectin proteins making these living photonic systems self-assemble into the observed biophotonic structures.