Carbon nano-onions for imaging the life cycle of Drosophila melanogaster.

Real-time X-ray or magnetic resonance imaging are known methods used for biomedical diagnosis. By the oral administration of barium meal, X-ray imaging can be extended for use in soft tissue imaging. The oral ingestion of a fluorescent probe is a new approach to imaging a living species. Here, water-soluble carbon nano-onions are introduced as a nontoxic, fluorescent reagent enabling Drosophila melanogaster (fruit flies) to be imaged alive. It is demonstrated that these water-soluble carbon nano-onions, synthesized from wood waste, colorfully image all the development phases of Drosophila melanogaster from its egg to adulthood. Oral ingestion of up to 4 ppm of soluble carbon nano-onions allows the optical fluorescence microscopy imaging of all the stages of the fruit fly life cycle without showing any toxic effects. The fluorescent Drosophila melanogaster excretes this fluorescing material upon the withdrawal of carbon nano-onions from its food.