No abstract

No abstract

Carbon quantum dots (C-QDs) are becoming a desirable alternative to metal-based QDs and dye probes owing to their high biocompatibility, low toxicity, ease of preparation, and unique photophysical properties. Herein, we describe fluorescence bioimaging of zebrafish using C-QDs as probe in terms of the preparation of C-QDs, zebrafish husbandry, embryo harvesting, and introduction of C-QDs into embryos and larvae by soaking and microinjection. The multicolor of C-QDs was validated with their imaging for zebrafish embryo. The distribution of C-QDs in zebrafish embryos and larvae were successfully observed from their fluorescence emission. the bio-toxicity of C-QDs was tested with zebrafish as model and C-QDs do not interfere to the development of zebrafish embryo. All of the results confirmed the high biocompatibility and low toxicity of C-QDs as imaging probe. The absorption, distribution, metabolism and excretion route (ADME) of C-QDs in zebrafish was revealed by their distribution. Our work provides the useful information for the researchers interested in studying with zebrafish as a model and the applications of C-QDs. The operations related zebrafish are suitable for the study of the toxicity, adverse effects, transport, and biocompatibility of nanomaterials as well as for drug screening with zebrafish as model.

Structural modifications are a successful and commonly used approach to tune the emission properties of diverse fluorophores, but extending this approach to heavy-atom-free persistent luminophores has so far been unsuccessful. Here we employed a novel strategy to demonstrate triplet-triplet energy transfer from an organic room-temperature phosphor (RTP) with persistent luminescence to an organic molecule with thermally activated delayed fluorescence (TADF). We illustrated this approach by preparing heavy-atom-free composite crystals of an RTP with a long-lifetime emission and a red emissive organic fluorophore with TADF to yield materials with emission above 650 nm. The emission arose from the triplet excited state of an acceptor undergoing thermally activated reverse intersystem crossing (RISC) to the emissive S 1 state. Such composite crystal is the first organic material with persistent TADF, achieved by triplet-triplet energy transfer.

No abstract