Subcellular fluorescence imaging for BHK cell and multiple sensing based on carbon dots with two strong emission peaks

摘要

Graphical abstractA novel kind of nitrogen-doped carbon dots (N-CDs) was developed with unprecedented properties, which can emit two strong emission peaks at about 450nm and 540nm under a single-wavelength ultraviolet-light excitation, label nucleus of BHK cells, and detect Fe3+ ion and ascorbic acid as “on-off-on” probe.Display OmittedHighlights•Nitrogen-doped carbon dots were developed with unprecedented properties.•Such N-CDs possess two strong emission peaks at 450nm and 540nm.•Emission peaks were influenced by pH, leading to fluorescent color change.•The as-prepared N-CDs can label BHK nucleus for fluorescent imaging.•These N-CDs act as promising “on-off-on” probes for Fe3+and AA detection.AbstractWe develop a novel kind of nitrogen-doped carbon dots (N-CDs) with unprecedented properties through hydrothermal treatment of soluble starch and ethylenediamine. Such N-CDs can emit two strong emission peaks at about 450nm and 540nm under a single-wavelength ultraviolet-light excitation. The intensity ratios of the two emission peaks are influenced by pH values, leading to the change of fluorescent colours, which can be utilized to detect solution pH by the change of fluorescent colours. Most importantly, N-CDs can act as fluorescence probes for labelling cell nucleus of BHK cells selectively, indicating that the as-prepared N-CDs have specific targeting towards nucleus cells. In addition, the fluorescence intensity can be quenched by Fe3+ion and restored by ascorbic acid effectively. The detection limits for Fe3+and AA were 84.9nM and 62.1nM, respectively.