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

非技术摘要：这个职业奖由材料研究部的生物材料计划，以及宾夕法尼亚大学化学、生物工程、环境和运输系统(ENG/CBET)的纳米生物传感器计划共同资助，旨在研究在软体动物中发现的一类蛋白质的自组装。软体动物是诸如鱿鱼、章鱼、鼻涕、文蛤和牡蛎等动物。这些动物中的许多都是令人惊叹的彩虹色，这种彩虹色被用来伪装，用来发出信号，就巨蛤来说，用来优化与共生藻类的光合作用。这个项目试图了解这些彩虹结构的进化，并了解它们的结构是如何从制造它们的蛋白质中出现的。为了做到这一点，PI将使用来自海洋动物收藏、材料表征技术和分子动力学建模的独特组合。这些结构的分级有序的复杂性往往远远超过目前合成制造的能力，因此了解动物是如何制造这些光学材料的将有助于深入了解分级长度尺度小于一微米的材料的制造。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)方面发挥了主导作用，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实地工作方面的高度跨学科培训。该奖项还将资助费城公立学校的高中生暑期实习，这些高中生通过参加宾夕法尼亚大学的暑期物理夏令营而被评为具有科学天赋的学生。这些实习的目标是提供研究经验和实践知识的机会，帮助这些学生在被高选择性的学院和大学录取方面具有竞争力。最终目标是能够增加对STEM职业感兴趣的学生数量。技术摘要：鱿鱼、章鱼和文蛤等软体动物建造了一系列具有惊人光学/光子复杂性和复杂性的活体光学设备，如结构伪装涂层、渐变折射率透镜、太阳辐射分配器和特定波长的光导。与鱼、蝴蝶和鸟类中的彩虹状结构不同，软体动物中的“虹膜细胞”是由静止的细胞形成的，高指数部分是由活跃细胞质中的蛋白质密集组装而产生的。这些光学共振细胞似乎比其他类群中的系统允许更多的结构多样性，并已进化为解决比任何其他动物群体更广泛的进化光学问题，如水下视觉、发射伪装、反射伪装和高效光合作用的光分配。对鱿鱼反射素蛋白和S晶体蛋白的一些新观察表明，“片状胶体”是理解这些活的光子系统组装的最有信息量的理论范式。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反射素的蛋白质是否以及如何使这些活的光子系统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.