Inorganic Biological Hybrid Systems for Photochemical Biosynthesis

用于光化学生物合成的无机生物混合系统

• 批准号: 1507914
• 负责人: Peidong Yang
• 金额: $ 39万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507914&HistoricalAwards=false
• 关键词: Inorganic; Biological; Hybrid; Systems; Photochemical

Non-technicalEnergy and environmental problems represent one of the greatest challenges facing humankind in this century. Despite tremendous efforts to develop renewable energy sources, still the majority of energy used is derived from non-renewable fossil fuels. Reducing carbon dioxide, an abundant carbon source, into value added fuels using a renewable energy input (i.e. artificial photosynthesis) would allow us to reduce our dependence on conventional fossil fuels, mitigate CO2 emissions and make our society more sustainable. Furthermore, chemical fuels produced from carbon dioxide could be readily implemented in the current energy infrastructure allowing a quick and smooth transition toward a renewable energy society. This research is aimed at solving several problems: harvesting solar electricity using semiconductor nanocrystals, synthesizing a variety of useful chemicals with nanocrystal/bacteria hybrids, and disposing of a troublesome waste product produced in very large quantities, i.e., carbon dioxide. This research is also highly cross-disciplinary as the confluence of two disparate technologies to produce a solution to a problem, i.e., materials science to produce semiconductor nanocrystals, and biotechnology to use the electrons and holes produced by the nanocrystals to general value-added chemicals. The insights gained in this study possesses the potential to supplant the reliance on petrochemical routes to chemical synthesis for fuels, fertilizers, industrial and commodity chemicals, polymers, pharmaceuticals, and more, while simultaneously providing a path towards carbon capture and reduction of atmospheric CO2 levels.TechnicalNatural photosynthesis relies upon a series of light harvesting proteins, which are optically limited to an absorption peak, only capable of utilizing a relatively narrow region of the solar spectrum and are susceptible to damage by higher energy photons. In comparison, inorganic, solid-state semiconductors, which form the basis of high efficiency commercial photovoltaic cells, surpass their biological analogues, possessing an absorption band, above which all higher energy photons can be collected for chemical work. However, such inorganic light harvesting schemes are quite costly, requiring scarce elements in exceptionally high purity, and energy intensive synthesis schemes. Additionally, unlike their biological counterparts, many of the highest performing materials are fundamentally unstable, susceptible to a variety of damage and degradation pathways with no built in mechanism for self-repair. One might envision a hybrid system, in which the best of both worlds are combined for the purpose of photochemical biosynthesis: the optoelectronic properties of inorganic chemical systems, with the synthetic, self-regenerative properties of biological systems. Through such a symbiotic relationship, in which each half augments the capabilities of the other, it is possible to design a new type of biotic-abiotic hybrid biomaterial that surpasses the capabilities of their individual components.The objective of this research is to design and explore the fundamental biotic-abiotic interfaces of a model system for inorganic-biological artificial photosynthesis of a diversity of chemical products utilizing CO2 as the sole carbon source. This model system will require several phases: 1) selection of a biological component for chemical synthesis; 2) selection of an inorganic light harvester; 3) exploration of the synergistic effects of the inorganic-biological hybrid system; and 4) detailed study of the fundamental mechanisms at the newly formed biotic-abiotic interfaces. This proposed work represents a first foray into relatively unexplored territory: the energy transduction between semiconductors and whole cell microorganisms. Of what the PI believe to be the first work of its kind is the examination of the self-photosensitization of a microorganism, in which bacteria is able to synthesize its own inorganic semiconductor light harvester, and carry out normal metabolic function through this new form of energy transduction. The proposed work will serve as a foundation for teaching and training students highly interdisciplinary skills in chemistry, physics, biology and materials engineering for renewable energy research.

非技术能源和环境问题是本世纪人类面临的最大挑战之一。尽管付出了巨大的努力来开发可再生能源，但所使用的大部分能源仍然来自不可再生的化石燃料。使用可再生能源输入（即人工光合作用）将二氧化碳（一种丰富的碳源）减少为增值燃料，将使我们能够减少对传统化石燃料的依赖，减少二氧化碳排放并使我们的社会更加可持续发展。此外，由二氧化碳生产的化学燃料可以很容易地在当前的能源基础设施中使用，从而实现向可再生能源社会的快速平稳过渡。这项研究旨在解决几个问题：使用半导体纳米晶体收集太阳能，用纳米晶体/细菌混合物合成各种有用的化学品，以及处理大量产生的麻烦的废物，即二氧化碳。这项研究也是高度跨学科的，因为两种不同的技术融合在一起来解决问题，即材料科学生产半导体纳米晶体，生物技术利用纳米晶体产生的电子和空穴生产一般增值化学品。这项研究获得的见解有可能取代燃料、化肥、工业和商品化学品、聚合物、药品等化学合成对石化途径的依赖，同时提供碳捕获和减少大气二氧化碳水平的途径。技术自然光合作用依赖于一系列光捕获蛋白质，这些蛋白质在光学上仅限于 吸收峰，只能利用太阳光谱中相对较窄的区域，并且容易受到较高能量光子的损坏。相比之下，构成高效商业光伏电池基础的无机固态半导体超越了它们的生物类似物，拥有吸收带，在该吸收带之上可以收集所有更高能量的光子以进行化学工作。然而，这种无机光捕获方案非常昂贵，需要极高纯度的稀有元素，并且合成方案需要能源密集型。此外，与生物材料不同的是，许多性能最高的材料从根本上来说是不稳定的，容易受到各种损坏和降解途径的影响，并且没有内置的自我修复机制。人们可能会设想一种混合系统，其中将两个领域的优点结合起来以实现光化学生物合成：无机化学系统的光电特性与生物系统的合成、自我再生特性。通过这种共生关系，其中每一半都增强了另一半的能力，有可能设计出一种新型的生物-非生物混合生物材料，超越其各自成分的能力。本研究的目的是设计和探索利用二氧化碳作为多种化学产品的无机-生物人工光合作用模型系统的基本生物-非生物界面。 唯一的碳源。该模型系统需要几个阶段：1）选择用于化学合成的生物成分； 2）无机光收集器的选择； 3）探索无机-生物杂化系统的协同效应； 4）详细研究新形成的生物-非生物界面的基本机制。这项拟议的工作代表了对相对未经探索的领域的首次尝试：半导体和全细胞微生物之间的能量转换。 PI认为此类工作中的第一个工作是对微生物的自光敏化的检查，其中细菌能够合成自己的无机半导体光收集器，并通过这种新形式的能量转换来执行正常的代谢功能。拟议的工作将为教学和培训学生在可再生能源研究的化学、物理、生物学和材料工程方面的高度跨学科技能奠定基础。