Carbon dots (CDs), as an intriguing class of nanomaterials, have garnered a great deal of attention in recent years. These carbon-based materials possess excellent fluorescence (FL) properties, which renders them highly appealing in a wide range of applications.

Researchers at Suzhou Institute of Biomedical Engineering and Technology (SIBET) of the Chinese Academy of Sciences recently designed a novel aggregation-induced emission (AIE) carbon dots (Y-CDs) for visualization of nuclear and zebra fish long-term imaging.

Despite of their excellent characteristics, CDs often encounter limitation of aggregation caused quenching (ACQ) effects. In solid or aggregated state, the FL of CDs significantly decrease or even disappear entirely, which has limited the development and application of CDs.

DONG Wenfei and his team at SIBET synthesized a novel AIE CDs by introducing rare earth elements (Yb and Er), called Y-CDs. Y-CDs exhibited excellent optical properties, which included excitation-independent emission, pH-responsive and temperature-sensitive properties,” said DONG. “They were found to have low requirement in terms of incubation time, and could achieve good imaging effect when incubation concentration was low.”

Y-CDs demonstrated excellent targeting capability toward the nucleus in HeLa cells. In zebrafish and zebrafish embryos, Y-CDs showed biocompatibility and safety in long-term imaging experiments, and  enabled selectively visualizing of crystalline and digestive systems of the zebrafish. Their study prove that Y-CDs can effectively penetrate zebrafish and zebrafish embryos and also have tissue affinity for juveniles, which provides a novel material choice for zebrafish imaging, according to KOU Xinyue, first author of the research.

The synthesized Y-CDs with rare earth elements showed great promise for a variety of imaging and biological sensing applications. Further research and development in this area could result in the advancement of bioimaging techniques and the exploration of new applications in biology and medicine, said DONG.

The research results entitled “Rare earth-modified yellow carbon dots for long-term imaging in cells and zebrafish” were published in Materials & Design.

The research was supported by the National Key R&D Program of China, National Natural Science Foundation of China, etc.

Fig.1 Schematic illustration for the synthesis of Y-CDs, and the application for nucleus imaging and selectively visualizing the crystalline and digestive systems of the zebrafish. (Image by SIBET)

Fig. 2 (a) The confocal fluorescence images of zebrafish embryos and juvenile zebrafish imaged with Y-CDs; (b) The long-term imaging effects of Y-CDs on zebrafish embryos (12 h to 10 days); (c) The biosafety test of Y-CDs during long-term imaging of zebrafish embryos. Scale bar: 250 μm. (Image by SIBET)

Contact

XIAO Xintong

Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (http://www.sibet.cas.cn/)

Phone: 86-512-69588013

E-mail: xiaoxt@sibet.ac.cn