Fe-Sensitive Carbon Dots for Detection of Fe in Aqueous Solution and Intracellular Imaging of Fe Inside Fungal Cells.

In this article, the Fe-sensitive carbon dots were obtained by means of a microwave-assisted method using glutamic acid and ethylenediamine as reactants. The carbon dots exhibited selective response to Fe ions in aqueous solution with a turn-off mode, and a good linear relationship was found between (F-F)/F and the concentration of Fe in the range of 8-80 μM. As a result, the as-synthesized carbon dots can be developed as a fluorescent chemosensor for Fe in aqueous solution. Moreover, the carbon dots can be applied as a fluorescent agent for fungal bioimaging since the fungal cells stained by the carbon dots were brightly illuminated on a confocal microscopy excited at 405 nm. Furthermore, an increase in the concentration of intracellular Fe could result in fluorescence quenching of the carbon dots in the fungal cells when incubated in the Tris-HCl buffer solution containing Fe. However, due to EDTA might hinder Fe(III) to enter the fungal cells, incubation in Fe(III)-EDTA complex solution exerted negligible effect on the fluorescence of fungal cells labeled by the carbon dots. Therefore, the carbon dots can serve as a potential probe for intracellular imaging of Fe inside fungal cells.