Scalable and continuous nanomaterial integration with transgenic fibers for enhanced photoluminescence

Abstract

For widespread practical translation and utilization of plasmonics and nanophotonics, there is always a need for scalable, cost-effective, eco-friendly, and nontoxic production of nanomaterials and nanostructures. As alternative fabrication and synthesis approaches, insects have received considerable attention as bioreactors and biosynthesis factories. However, scalable fabrication of plasmonic nanomaterials and their integration into flexible and wearable components are still limited. We show that a unique combination of a silkworm factory and green chemistry appears to be an effective hybridizing platform for integrating natural biomaterials and metal nanoparticles. Our approach is inspired by a two-century-old method of increasing the weight of silk fabrics for high price (also known as silk weighting). The reported plasmonics hybridization of silk results in the formation of silver nanoparticles in the interfibrillar space of silk fibers, which is manifested by the ‘lustrous’ or ‘silvery’ color of silk. We further demonstrate the plasmon-enhanced photoluminescence of far-red fluorescent protein in silk produced by genetically engineered silkworms (i.e., silkworm transgenesis). Our results provide the groundwork for exploiting native silk as a photonic hybridization platform to implement embedded functionalities in a fiber geometry, which could easily be woven or constructed into large-area and continuous fabrics using existing textile infrastructures in a sustainable manner.