20-BBSRC/NSF-BIO Quantum-enhanced long-range energy capture

主要农作物的自然光合作用显示，太阳能到生物质的总转换效率仅为2-3%。人们对通过基因操作改善这一数字非常感兴趣，因为到2050年，全球农作物产量必须增加约100%-110%，才能养活预计90亿-100亿人口。一种选择是将吸收的太阳能的光谱范围扩大到超过目前720纳米的限制。由于细菌光合作用复合体利用细菌叶绿素吸收700-1050 nm区域的光，合成生物学可以用来增强具有类似能力的植物。作为实现这一目标的第一步，实现从植物蛋白质LHCII到细菌蛋白质RC-LH1的高效能量转移是至关重要的，拟议的工作将进一步推动这一过程。虽然光合作用的整体效率较低，但初始步骤表现出高量子效率，因为高达95%的吸收光子驱动电荷分离事件。理解光收集网络中的组织和相互作用如何实现这种效率，包括拟议中的、但仍有争议的量子现象的作用，将为人造光收集设备提供蓝图。最近在光刻图案化系统中增加的能量传播和激子-等离子体耦合到衬底的观察表明，通过这些光子系统的设计可以增强纳米尺度的相互作用。之前的工作已经探索了LHC中的量子现象，并发现了离域振动和振动相干持续数百飞秒的证据。到目前为止，这种影响已经用复杂的光谱技术进行了研究，但仅限于分离的蛋白质。非自然构象和相互作用在多大程度上可以增强量子相干性是一个悬而未决的问题。我们建议通过在LHC和RCS光刻图案化阵列中的非自然相互作用来设计这些效应，并将它们作为近自然脂质体系统的基准。以前，这种阵列是由单一组分构建的，并且只用基本的显微镜和光谱方法来询问，以确保它们的功能。在这里，我们将通过构建更复杂的非自然网络体系结构，并使用最新的先进的2D电子和关联光谱以及电子隧道AFM方法来前所未有地详细地询问它们，从而改变我们的理解。这些努力将通过提供对在生理温度下促进量子一致性的因素的机械洞察，并揭示此类行为增强功能的机制，来促进生物学理解。

Natural photosynthesis in major crop plants shows an overall efficiency of solar energy to biomass conversion of just 2-3%. There is great interest in improving this figure through genetic manipulation because global crop production must increase by an estimated 100-110% by 2050 to feed the projected 9-10 billion population. One option is to widen the spectral range of absorbed solar energy beyond the current limit of 720 nm. Because bacterial photosynthetic complexes use bacteriochlorophyll to absorb light in the 700-1050 nm region, synthetic biology could be used to augment plants with similar abilities. As a first step towards this goal, realising efficient energy transfer from the plant protein, LHCII, to the bacterial protein, RC-LH1, is crucial and will be furthered by the proposed work.While the overall efficiency of photosynthesis is low, the initial steps exhibit high quantum efficiency as up to 95% of absorbed photons drive a charge separation event. Understanding how the organisation and interactions within the light-harvesting network achieve this efficiency, including the proposed, yet debated, role of quantum phenomena, would provide a blueprint for artificial light-harvesting devices. Recent observations in lithographically patterned systems of in- creased energy propagation and exciton-plasmon coupling to the substrate suggest that nanoscale interactions can be enhanced through the design of these photonic systems. Previous work has probed for quantum phenomena in LHCs, and found evidence of delocalised vibrational and vibronic coherences persisting for hundreds of femtoseconds. To date, such effects have been studied with sophisticated spectroscopic techniques, yet exclusively within isolated proteins. The extent to which quantum coherence may be enhanced by non-native conformations and interactions is an open question.We propose to engineer these effects through non-native interactions within lithographically patterning arrays of LHCs and RCs, benchmarking them to near-native liposomal systems. Previously, such arrays were constructed from a single component and have only been interrogated with basic microscopic and spectroscopic methods to ensure their functionality. Here we will engender a step-change in our understanding by constructing more complex non-natural network architectures and interrogating them in unprecedented detail using the latest advanced 2D electronic and correlation spectroscopy and electron-tunnelling AFM methods. These efforts will progress biological understanding by providing mechanistic insight into the factors that promote quantum coherence at physiological temperatures and revealing the regimes where such behaviours enhance function.