Biomaterials Interfaces for Photoactive Proteins

非技术：范德比尔特大学和田纳西州立大学将探索将蛋白质整合到设备中的基本进展，以加速生物混合太阳能电池的发展，以产生负担得起的可再生能源。一个由两名化学家和一名化学工程师组成的团队将在这个项目中合作开发受自然启发的太阳能电池，这种电池使用来自绿色植物的蛋白质作为光活性元素。蛋白质复合物光系统I （PSI）和光系统II （PSII）驱动植物光合作用，是高效的太阳能转换器。该团队的成员在将PSI和PSII薄膜与电极表面集成以设计和构建具有光电流的光电化学电池方面具有丰富的经验，在过去的五年中，光电流已经提高了近106倍，现在在许多成熟技术的数量级内。该研究项目将解决关键的基础生物材料问题，以大大提高基于光系统的太阳能电池的性能。该项目的研究团队将以他们在范德比尔特大学和田纳西州立大学（HBCU）将研究与教育相结合的良好记录为基础，通过研究经验和跨学科课程，促进工程和化学领域研究生和本科生研究人员的跨学科教育。通过菲斯克大学和田纳西州的HBCUs，将来自代表性不足群体的学生与范德比尔特暑期学院的K-12课堂外展和范德比尔特学生科学志愿者相结合，建立了一个既定的外展项目。技术：在这个项目中，来自范德比尔特大学和田纳西州立大学的团队将开发一种仿生方法来定向电极表面的PSI，探索将这些蛋白质与导电材料连接的新方法，以促进电子在蛋白质之间的流动，并促进能带能量排列，以实现生物混合太阳能转换的另一个量子飞跃。首先，用表面活性配体选择性地修饰类囊体膜内暴露的PSI基质面，然后将修饰后的蛋白质释放到表面进行定向组装，从而大大增强了PSI在电极表面的取向。实现这些生物分子光电二极管的均匀定向，而不依赖于昂贵和缓慢的替代方法，将大大提高生物混合性能。其次，通过将还原氧化石墨烯、氧化还原聚合物和半导体纳米颗粒连接到活性PSI位点，可以提高PSI膜内的导电性。这些定向和更导电的PSI薄膜将与两种类型的电极系统在湿和固态系统的接口。以该小组最近的成功为基础，PSI薄膜将与具有适当能级的半导体相连接，以引导电子单向流过电路。此外，将设计、制造和优化一种全碳基太阳能电池，其中PSI薄膜夹在相反掺杂的原子薄石墨烯薄片之间，产生“堆叠”结构，入射光只有轻微的阻抗。这些进展也将应用于PSII在衬底电极上的界面和光电化学。pi将创建外联组件和工具包，用于在初中和高中环境中构建和演示这些设备。

Non-Technical:This award to Vanderbilt and Tennessee State Universities will explore fundamental advances in the integration of proteins into devices to speed the development of biohybrid solar cells for the generation of affordable, renewable power. A team of two chemists, and a chemical engineer will collaborate in this project to develop nature-inspired solar cells that use proteins from green plants as the photo-active elements. The protein complexes Photosystem I (PSI) and Photosystem II (PSII) drive photosynthesis in plants and are highly efficient solar converters. Members of this team have experience in integrating PSI and PSII films with electrode surfaces to design and construct photoelectrochemical cells with photocurrents that have improved by a factor of nearly 106 over the past five years and are now within an order of magnitude of many mature technologies. This research project will address key fundamental biomaterials issues to greatly enhance the performance of photosystem-based solar cells. The research team for this project will build on their strong track record of integrating research with education at Vanderbilt and Tennessee State University, an HBCU, by promoting the interdisciplinary education of graduate and undergraduate researchers in engineering and chemistry through research experiences and interdisciplinary coursework. An established outreach program to include students from under-represented groups through Fisk and Tennessee State HBCUs is combined with K-12 classroom outreach in the Vanderbilt Summer Academy and Vanderbilt Student Volunteers for Science.Technical:In this project, the team from Vanderbilt and Tennessee State will develop a biomimetic approach to orient PSI on electrode surfaces, explore new ways of interfacing these proteins with conductive materials to facilitate electron flow to/from the proteins, and promote band energy alignment with the goal to achieve another quantum leap in biohybrid solar energy conversion. First, PSI orientation at electrode surfaces will be greatly enhanced by selectively modifying the exposed stromal face of PSI within the thylakoid membrane with surface-active ligands before releasing the modified protein for directed assembly onto surfaces. Achieving uniform orientations of these biomolecular photodiodes without the reliance on expensive and slow alternative methods would greatly advance biohybrid performance. Second, the conductivity within PSI films will be promoted by wiring reduced graphene oxide, redox polymers, and semiconductor nanoparticles to the active PSI sites. These oriented and more conductive PSI films will be interfaced with two types of electrode systems in both wet and solid-state systems. Building from the group's recent success, PSI films will be interfaced with semiconductors with appropriate energy levels to guide electron flow unidirectionally through the circuit. In addition, an all-carbon-based solar cell in which PSI films are sandwiched between oppositely doped, atomically thin graphene sheets to yield "stacked" architectures with only slight impedance of incoming light will be designed, fabricated, and optimized. These advances will also be applied to the interfacing and photoelectrochemistry of PSII onto substrate electrodes. The PIs will create outreach components and kits for building and demonstrating these devices in the middle school and high school settings.