Exploring Energy and Charge Transport Mechanisms in Natural Light Harvesting and DNA

光合生物利用太阳能为地球上大多数生物活动提供动力。光合生物利用太阳能为地球上大多数生物活动提供动力。在植物的叶绿体内，阳光被数十亿叶绿素分子吸收，用于驱动光合作用;二氧化碳和水被转化为植物生长所必需的单糖。这一非凡的自然过程经常达到100%的效率：吸收的每一个光子都转化为化学能。迄今为止，我们利用人造光伏技术利用太阳能发电的努力远没有那么有效。为了满足不断增长的全球能源需求，我们的社会必须开发可再生和更高效的光伏设备，以充分利用丰富的太阳能通量。除了好处，阳光也有威胁：阳光中的紫外线（UV）成分对地球上的生命可能非常有害。脱氧核糖核酸（DNA）是地球上所有生物的源代码。如果DNA吸收紫外线，可能会引发潜在的有害光化学反应，如电子喷射或键断裂。除了好处，阳光也有威胁：阳光中的紫外线（UV）成分对地球上的生命可能非常有害。脱氧核糖核酸（DNA）是地球上所有生物的源代码。如果DNA吸收紫外线，可能会引发潜在的有害光化学反应，如电子喷射或键断裂。通过了解这些紧密堆积的多发色团系统中分子之间能量流动的路线和时间尺度，我们将寻求在分子水平上对支撑能量传输和电荷分离的机制的基本理解。这些见解将提供对自然光捕获或DNA中固有的光保护/光损伤途径的更基本的理解。该项目将使用最先进的超快激光光谱学，如二维电子振动光谱学和二维电子光谱学，创建具有飞秒时间分辨率的分子之间的能量/电荷流图（1 fs =百万分之十亿分之一秒）在自然光捕获蛋白质和模型DNA系统。

Photosynthetic organisms harness energy from sunlight to power most biological activity on Earth. Photosynthetic organisms harness energy from sunlight to power most biological activity on Earth. Inside chloroplasts of plants, sunlight is absorbed by billions of chlorophyll molecules and used to drive photosynthesis; carbon dioxide and water are converted into simple sugars essential for plant growth. This remarkable natural process regularly achieves 100% efficiency: every photon absorbed is converted into chemical energy. Our efforts to harness solar energy with man-made photovoltaic (PV) technology to generate electricity have, to date, been far less effective. To meet the ever-growing global energy demands, it is imperative for our society to develop renewable and more efficient PV devices that can take full advantage of the abundant solar flux. As well as benefits, sunlight harbours threats: the ultraviolet (UV) component of sunlight is potentially very harmful for life on Earth. Deoxyribonucleic acid (DNA) is the source code for all living organisms on our planet. If DNA absorbs the UV light, potentially deleterious photochemical reactions can be initiated, such as ejection of an electron or bond breaking. As well as benefits, sunlight harbours threats: the ultraviolet (UV) component of sunlight is potentially very harmful for life on Earth. Deoxyribonucleic acid (DNA) is the source code for all living organisms on our planet. If DNA absorbs the UV light, potentially deleterious photochemical reactions can be initiated, such as ejection of an electron or bond breaking. These can lead to destruction of our genetic code and cancerous mutations.By understanding the routes and timescales of energy flow between molecules in these tightly packed multi-chromophore systems, we will seek to gain a fundamental understanding on the molecular level of the mechanisms that underpin energy transport and charge-separation. These insights will provide a greater fundamental understanding of natural light harvesting or the intrinsic photoprotection/photodamage pathways in DNA.This project will use state of the art ultrafast laser spectroscopies such as two-dimensional electronic-vibrational spectroscopy and 2D electronic spectroscopy, to follow create a map of energy/charge flow between molecules with femtosecond time resolution (1 fs = one millionth billionth of a second) in natural light harvesting proteins and model DNA systems.