Recombinant Spider Silk-based Hybrid Materials for Advanced Energy TechnologyPart of:
Organic matrices can be used as a template for mineralization. Such hybrid materials possess several advantages over purely inorganic or organic materials such as a higher mechanical or chemical stability or multi-functionality by presenting different functional components on their surface. In recent studies, preparation of TiO2 / Au “Janus”-particles showing a side-by-side morphology was successfully demonstrated. These particles allow photocatalytic hydrogen production. The aim of the presented project is the combination photoactive inorganic nanoparticles with an organic matrix allowing for a high aspect ratio. Spider silk can be spun into Janus fibers providing a two-side morphology as found in Janus particles. Due to genetic engineering, both sides can be individually addressed by specific chemical interactions. Thereby it was possible to modify the fibers selectively with TiO2 and gold. Therefore, two spider silk proteins were designed, eADF4(C16)-TiO2 (engineered Araneus diadematus fibroin 4) with an overall negative charge bearing a peptide sequence, which was found to bind to TiO2 nanoparticles, and ntagCyseADF4(κ16) with an overall positive charge bearing a thiol group for gold binding. Using e-spinning, these two proteins were processed into Janus fibers, held together by electrostatic interactions between the positively and negatively charged spider silk proteins.