Dewey Holten

A small team of chemists, having learned the secrets of light absorption from chlorophylls a and b, can now tune molecules to absorb anywhere in the solar spectrum. They are using this facility to synthesize pigments that fill gaps in the sunlight absorbed by native pigments and to push deeper into the infrared than any native pigment.

The Department of Energy has awarded the Photosynthetic Antenna Research Center (PARC) $14.4 million for continuing research on natural and bio-inspired systems for harvesting the sun’s energy. The center, which is hosted by Washington University in St. Louis, was one of 32 projects selected for funding from among more than 200 proposals and one of only 22 to receive second-round funding.

In the Aug. 6, 2013, online edition of Chemical Science, a team of scientists describes a testbed for light-harvesting antennas, the structures that capture the sun’s light in plants and bacteria. Prototype designs built on the testbed soak up more of the sun’s spectrum and are far easier to assemble than synthetic antennas made entirely from scratch. They offer the best of both worlds, combining human synthetic ingenuity with the repertoire of robust chemical machinery selected by evolution.

At WUSTL’s Photosynthetic Antenna Research Center scientists have succeeded in making a light-harvesting antenna from scratch. The new antenna, modeled on the chlorosome found in green bacteria, is a giant assembly of pigment molecules. Chlorosomes allow green bacteria to photosynthesize even in the dim light in ocean deeps. The new technology may one day transform solar-powered devices.