Amphiphilic carbon dots for sensitive detection, intracellular imaging of Al³⁺

In this paper, a simple and effective method was designed to synthesize hydrophobic carbon dots. Subsequently, amphiphilic fluorescent carbon dots (A-CDs) were synthesized by further surface modification. The result A-CDs show excellent optical properties with a quantum yield of 16.9%. It was interestingly found that morin (MR) and its fluorescent metal-ion complex (MR-Al³⁺) can successfully coordinate on the surface of A-CDs, the emission of A-CDs completely overlapped the absorption peak of MR-Al³⁺. Thus, the prepared A-CDs can be used as an effective fluorescent probe for Al³⁺ based on a fluorescence resonance energy transfer process. The sensing platform can realize real-time detection of Al³⁺ within 0.5 min. The fluorescence signals of the system were linearly correlated with the concentration of Al³⁺ over a range of 8–20 μM, with a detection limit of 0.113 μM. The method was also successfully applied to image the distribution of Al³⁺ in Human Umbilical Vein Endothelial Cells. - Highlights: • Amphiphilic carbon dots were obtained by simply modifying hydrophobic carbon dots. • Amphiphilic carbon dots/morin-Al³⁺ was used as a selective turn-on probe for Al³⁺. • The method was employed to intracellular imaging Al³⁺ in living cells.