Facile synthesis of magneto-fluorescent carbon dots by one-step microwave-assisted pyrolysis

Highlights: • Magneto-fluorescent CDs (MF-CDs) of approximately 2 nm were synthesized. • By one-step MW-assisted pyrolysis of citric acid, ethylenediamine and FeCl₂. • The MF-CDs exhibited superparamagnetic property. • The MF-CDs showed excitation-independent fluorescence property. -- Abstract: Magneto-fluorescent nanoparticles have been widely designed as multifunctional materials for various advanced applications. Here, a facile approach was established to synthesize magneto-fluorescent carbon dots (MF-CDs) of approximately 2 nm by one-step microwave-assisted pyrolysis of citric acid and ethylenediamine in presence of FeCl₂. The FT-IR and XRD analysis revealed the existence of iron oxides in the N-doped CDs. The magnetization analysis demonstrated the mixed phase of Fe₃O₄ with FeO in the MF-CDs with a saturation magnetization of 0.20 emu/g. The MF-CDs possessed the excitation-independent fluorescence with maximum PL intensity at excitation wavelength of 350 nm. The superparamagnetic and fluorescent behaviors make the designed ultrafine MF-CDs promising potential in multimodal cellular imaging.