Cell membrane-targeted near-infrared carbon dots for imaging of hydrogen sulfide released through the cell membrane

As a novel endogenous gasotransmitter, hydrogen sulfide (H2S) is involved in many physiological and pathological processes closely related to intracellular and intercellular signal transduction. Herein, carbon dots with near-infrared fluorescence (NIR-CDs) were prepared by the facile hydrothermal method. The near-infrared fluorescence peak of the NIR-CDs reached 683 nm, and the fluorescence intensity remained stable after storing at room temperature within 70 days. The prepared NIR-CDs can be directly used for quantitative determination of H2S with LOD of 56 nM. More remarkably, the NIR-CDs could specifically locate on cell membrane and have been successfully used for imaging of endogenous H2S efflux from cell on the cell membrane. This work provides a new strategy for the design of cell membrane-targeted CDs as well as the further study of the mechanism of gaseous signal molecules in signal pathways and cellular communication. Furthermore, we found that the distribution of NIR-CDs and the commercial cell membrane dye (DiO) on cell membrane has some difference, which may due to the complementary relationship between the NIR-CDs and DiO in solubility. This finding makes it possible to design fluorescent probes for targeted imaging in different functional regions of the cell membrane in the future.

Automated summary

In this study, carbon dots with near-infrared fluorescence were prepared using a hydrothermal method and successfully used for quantitative determination of H2S and imaging of endogenous H2S efflux from cell membrane. The NIR-CDs showed specific location on cell membrane and offered a new strategy for the design of targeted fluorescent probes in different functional regions of the cell membrane in the future.