Luminescent Fe₃O₄ Nanohybrid for Intra-Cellular Imaging and Combinatorial Chemo-Photothermal Therapy in Cancer

Highly stable water dispersible carbon dot decorated hybrid magnetic nanoparticles (FCDs) that combines magnetic Fe₃O₄ nanocrystals and fluorescent carbon dots (GUCDs) were successfully synthesized using a facile strategy. The resultant Fe₃O₄@GUCDs (FCDs) hybrid NPs not only validate excellent magnetic responsive properties (M_s = 33.5 emu g^-1) from the magnetic (Fe₃O₄) core, but also exhibit intriguing photo luminescent properties, including excellent photo stability from the CDs produced from glucose-urea mixture. The FCDs can enter the intracellular region and illuminate breast cancer cells (MCF-7), and showed a time and dose-dependent localization kinetics. Meanwhile, the presence of hydrophilic surface functional groups in FCDs contributes to the excellent stability in aqueous solutions as well as loading of the anti-cancer drug doxorubicin with a loading capacity of 22 mg g^-1. More importantly, the FCDs can absorb NIR irradiation followed by their conversion to heat energy to achieve photothermal modality. Thus, such nanostructured hybrid NPs (FCDs) demonstrate great potential towards advanced single platform nano-theranostics with combinatorial chemo-photothermal therapy.