Functional Protein-Semiconductor Nanotechnology in Microbial Factories

On average, each one of us now generates 7.8 kg of electronic waste per year, raising the need for a paradigm shift toward more sustainable methods of fabricating semiconductor nanotechnology. Nature offers a compelling blueprint: living systems construct complex mineral architectures including shells, bones, and magnetite nano-crystals, by assembling atoms with molecular precision through protein-guided processes. Inspired by these mechanisms, my postdoctoral research in the Baker Lab explored how de novo designed proteins can template the nucleation and growth of inorganic materials, including semiconductors. We designed proteins presenting regularly repeating interfaces that promoted the growth of hematite and the nucleation of ZnO under conditions where control proteins were ineffective. CryoEM analysis of a designed octahedral nanocage with incorporated ZnO-promoting interfaces revealed atomic density likely corresponding to growing ZnO directly adjacent to the designed nucleation sites. These results lay the groundwork for designing functional, highly defined nanoarchitectures that could potentially be fabricated in microbial factories.