Multifunctional carbon dots with high quantum yield for imaging and gene delivery

Carbon dots (CD) are luminescent nanomaterial with unique properties that show great potential in many applications. Herein, branched polyethyleneimine-based carbon dots (PCD) are prepared from branched polyethyleneimine by oxidation and a modified hydrothermal reaction. Structure and composition analysis indicate that obtained PCD possesses a 3–4 nm in diameter and a graphitic structure with lattice spacing of 0.30 nm. The PCD has a quantum yield of 54.3%. The bright photoluminescence shows that it can be used for cell imaging. The PCD exhibits extremely good biocompatibility and can be applied for gene delivery. Because of its specific nanostructure and photoluminescence property, the multifunctional PCD prepared shows potential for applications in bioimaging and gene delivery.