Design and synthesis of hydrophobic carbon dots for potential application as bio-imaging probe

Abstract

Carbon dots (CDs) have been extensively researched as promising fluorescent nanomaterials, with a focus on yellowish-orange or solid-state fluorescence, which is less commonly reported. Hydrophobic carbon dots (HCDs) were successfully synthesized through a one-pot solvothermal treatment, exhibiting blue dispersed emission and yellowish-orange aggregation-induced emission. The introduction of water led to F-HCD aggregation, switching off the blue emission and turning on the yellowish-orange fluorescence due to π-π stacking interactions and restriction of intramolecular rotation around disulfide bonds, respectively The reversible on-off fluorescence behavior of F-HCD was demonstrated, with the ability to switch between blue and yellowish-orange emissions by dissolving and re-dissolving the F-HCD powder. Similar to conventional organic dyes, F-HCD have the ability to function as membrane probes for the investigation of membrane dynamics because they show strong yellowish-orange emission in the ordered phase of the lipid bilayer and blue emission in the disordered phase.