University of Otago, New Zealand


Te Tari Hua-Ruanuku

Gordon Group Researchers

John Earles
Characterisation of Porphyrin-Maquette interactions

John graduated in 2010 and is now postdoc at the University of Tromso in Norway.

One of the great challenges of the 21st Century is the development of a sustainable clean fuel. Nature has already realized this goal in the form of photosynthesis, the amazingly efficient solar energy collection carried out by one of the most elaborate nano-scale biological machines in nature. Photosynthetic processes employ light-harvesting (LH) complexes to capture dilute sunlight and funnel the energy to a chlorophyll (porphyrin, Fig. 1b) dimer in the reaction centre (RC, Fig. 1). At the heart of this incredible process are the chlorophyll antennae, which contain from 2 to 300 closely spaced chlorophyll molecules (Fig. 1a) embedded in a lipoprotein matrix (e.g. LH1 and LH2, Fig. 1).

This research project aims to build and study light harvesting photosynthetic reaction centre mimics based on porphyrin arrays (artificial chlorophyll) and protein helices (maquettes), essentially structurally simpler analogues of natural photosynthetic systems (Fig. 2). Specifically at Otago, we are concerned with charaterising both the individual components and the porphyrin-maquette arrays using a variety of spectroscopic, computational and electrochemical techniques. This will be the first stage in the development of artificial photosynthesis, the creation of an efficient light harvesting biomimetic material that could be used as a photocatalyst, or in photonic devices and solar cells.