Altering the genome in an individual bacteriophage causes the virus to produce a novel protein. "Each bacteriophage has one protein but there are billions of bacteriophages," Knapp said. Researchers then examine how this huge, lab-generated library of proteins interacts with a foreign substance, often different types of metals.
Because of the number of different viruses and their respective proteins, the protein-substance encounters are not set up as individual meetings. Instead, the inorganic material is brought into contact with all of the different proteins at once. The proteins that don't stick or react to the metal or other foreign substance are washed away. "Bonding is the first step in how to manipulate these systems," Knapp explained.
Subsequent experiments then winnow the field to the most interesting results. The end results are varied: the same inorganic material will produce different types of crystals with a change in proteins Creating new substances out of a reaction between a protein and a metal comes as a result of the catalytic process many observe in high school chemistry. The big difference, Knapp said, is that most people don't associate proteins with this process, just inorganic minerals and elements.
A second technique involves combining inorganic materials with variants of a tube-shaped virus, known as M13, that measures 880 nanometers long and 6 nanometers in diameter. Instead of trying to form a third substance, researchers look to see whether the inorganic materials will bond into a coating around the virus.
In essence, researchers are forming fossils of the virus. The procedure could someday be employed to create nanowires, strands of atoms, generally made of pure silicon, that can be used to conduct electricity or light.
This process could also be used to create nanowires out of different substances or even composite nanowires that contain chemically distinct bands of varying materials. In January, Belcher's lab produced nanowires out of cadmium sulfide with this method.
The reactive and template methods are reflected in Cambrios' name, which derives from the Cambrian period. The Dyax, a bioscience company specializing in designer proteins, to use that company's technology in electronics.
"We're trying to put together proof of concepts," Knapp said. "What we have to do next is bring out materials that are functional, demonstrable and relevant."