Microwave assisted synthesis of luminescent carbonaceous nanoparticles from silk fibroin for bioimaging

•Synthesis of luminescent carbonaceous nanoparticles by microwave assisted hydrothermal treatment of silk fibroin.•The emission of the obtained carbonaceous nanoparticles is excitation dependent.•These carbonaceous nanoparticles possess high stability, low cytotoxicity and high biocompatibility.•These luminescent carbonaceous nanoparticles are used for live cell imaging.

Bombyx mori silk as a natural protein based biopolymer with high nitrogen content, is abundant and sustainable because of its mass product all over the world per year. In this study, we developed a facile and fast microwave-assisted synthesis of luminescent carbonaceous nanoparticles using Bombyx mori silk fibroin and silk solution as the precursors. As a result, the obtained carbonaceous nanoparticles exhibit a photoluminescence quantum yield of ~ 20%, high stability, low cytotoxicity, high biocompatibility. Most importantly, we successfully demonstrated bioimaging using these luminescent carbonaceous nanoparticles with excitation dependent luminescence. In addition, the microwave-assisted hydrothermal method can be extended to convert other biomass into functional nanomaterials.