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

点击翻译按钮获取中文摘要

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.