Solvent-free synthesis of recyclable hydrophobic carbon dots for highly selective detecting curcumin in food samples

A highly selective fluorometric method was developed for the specific determination of curcumin (Cur) based on hydrophobic carbon dots (HB-CDs) derived from flaxseed oil by a solvent-free reaction. The as-prepared HB-CDs possessed blue fluorescence emission (at 425 nm) with a fluorescence quantum yield (QY) of 21.1 %. It was that the fluorescence of HB-CDs could be quantitatively quenched by Cur, and the fluorescence quenching mechanism was proved to be a combination of dynamic and static quenching. The detection limit of the method for Cur was 20 nM with a linear response range of 0.2–200 µM. Additionally, HB-CDs can be quickly recovered from the tested solutions through solvent change precipitation. The developed HB-CDs based fluorescent method has been successfully applied for real food samples analysis with satisfactory results.