Researchers at the University of California, Santa Barbara, say they have succeeded in growing new mineral architectures by "directing the evolution" silicateins, which are the proteins responsible for the formation of silicon skeletons in marine sponges. For the first time, it was shown that it is possible to develop the enzymatic synthesis of a semiconductor using genetic engineering and molecular evolution. The implication? Companies may be able to use DNA information to develop their own "specialized" materials.
The key to the research was the use of silicateins, which are genetically encoded and are used as a blueprint for the creation of silica skeletons. According to the UCSB researchers, the process is very similar to the way animal and human bones are formed. In their study, polystyrene microbeads coated with specific silicateins were "put through a mineralization reaction by incubating the beads in a water-in-oil emulsion that contained chemical precursors for mineralization." As the silicateins reacted with the dissolved metals, "they precipitated them, integrating the metals into the resulting structure and forming nanoparticles of silicon dioxide or titanium dioxide." The result was the creation of a silicatein gene pool that enabled the researchers to pick silicateins with the specific properties they were looking for.
"This genetic population was exposed to two environmental pressures that shaped the selected minerals: The silicateins needed to make materials directly on the surface of the beads, and then the mineral structures needed to be amenable to physical disruption to expose the encoding genes," said Lukmaan Bawazer, the author a corresponding paper that is published in the current issue of the journal Proceedings of the National Academy of Sciences.
"The beads that exhibited mineralization were sorted from the ones that didn't, and then fractured to release the genetic information they contained, which could either be studied, or evolved further."
Bawazer said that he is now trying to evolve to evolve the research result into a functional device.